Toronto Mayor Rob Ford has refused to quit after Canadian police said they recovered a video appearing to show him smoking from a crack pipe.

Mr Ford, who has denied smoking crack, said he had "no reason" to resign.
Police have not gone into detail about the content of the mobile-phone footage but say it is consistent with previous media descriptions.
The saga has captivated the city since reports surfaced in May of the video's existence.
The video, first brought to light by journalists who reported seeing it, has never been released publicly.
Earlier, Toronto Police Chief Bill Blair told media of the video they had recovered from a computer hard drive, the contents of which he said "contained video images which appear to be those video images previously reported in the press".
Police have not filed criminal charges against Mayor Ford in connection with the video.
"There is nothing on that video that would support the laying of criminal charges," Mr Blair said. But he added it was an "issue of significant public concern and... a problem for the city".
He said he was "disappointed" by the video's contents.
Mr Ford told a gaggle of reporters outside his office on Thursday following the police statement that he wished "I could come out and defend myself".
"Unfortunately I can't because it's before the courts, and that's all I can say right now... I have no reason to resign," he said.
In May the Toronto Star newspaper said it had been approached by drug dealers trying to sell the video; two of its reporters viewed the video, but the organisation declined to pay for it.
A Gawker journalist also reported seeing the video and the organisation raised more than $200,000 in an online campaign to buy it, before being told by a source the video was "gone".
A photo depicting Mr Ford with two young men, which Gawker said they were given by the drug dealer selling the video, became notorious when it emerged that one of the men, Anthony Smith, had been shot dead on a Toronto street. Two men are facing murder charges in that case.
Reports of the mystery video's existence triggered a massive police investigation into the mayor and his associates, specifically a friend and occasional driver named Alexander "Sandro" Lisi.
Mr Lisi has since been charged with marijuana trafficking and possession. Police said on Thursday that he now faced a charge of extortion in relation to the video.
Documents released on Thursday also revealed a lengthy police surveillance operation against Mr Ford, with officers going through his rubbish and monitoring late-night meetings between Mr Ford and Mr Lisi.
The documents were released by court order on Thursday after petitioning by leading Canadian media outlets.
Several of Mr Ford's aides have resigned and his chief of staff was sacked in recent months. Some were interviewed by police in the case.
The case has riveted the city and its suburbs of just under six million people, Canada's largest. Mr Ford and his brother Doug, also a city councillor, have become divisive figures.
Mr Ford was elected in 2010 on a tough economic platform in which he promised to rein in spending and end the influence of special-interest groups.
His term in office has been plagued with allegations of substance abuse and regular confrontations with media, whom he accuses of organising a witch-hunt. He also narrowly escaped being removed from office in a conflict of interest case.
But he has drawn public sympathy with his folksy image and a very public battle with his weight.
Before Thursday's revelations, Mr Ford had pledged to run for re-election next year. He refused to comment to reporters at his home early on Thursday.


A GP groped female patients like a teenage boy "grabbing his first pair of boobs", a court has heard.

Dr Robert Lewis, 51, is accused of using routine examinations as a "pretext" to carry out assaults against women applying to join the ambulance and fire service.
Luton Crown Court heard he touched one woman's breasts like he was "polishing headlights".
Dr Lewis denies eight charges involving six women.
Jurors heard the offences took place at the Larksfield Surgery in Stotfold, near Hitchin, Hertfordshire.
Two women alleged he put his hand down their knickers and another described the doctor as being like a 14-year-old boy "grabbing his first pair of boobs" during an examination.
Another claimed he got her to bend over while he pulled out a tape measure and touched her bottom, the court heard.
Prosecutor Mark Fenhalls QC told the jury Dr Lewis had been acquitted of other allegations after a trial last November, but a jury could not decide on some and had found him guilty of others.
He said the new trial involved some of the allegations from the previous case but also new complainants who had come forward since.
"The assaults were subtle and carefully designed to avoid detection," Mr Fenhalls said.
"He was taking advantage of young women who were desperate to pass medicals.
"During some medical examinations, he used the pretext of breast and hernia checks to carry out assaults."
Dr Lewis, of Northbridge Street, Shefford, has pleaded not guilty to five charges of indecent assault and three charges of sexual assault between 1999 and 2007.
When questioned by the police in January 2013, the doctor denied indecently assaulting any patients, saying he always explained what he was doing and would get the patient's consent.
The trial continues.


Two teenagers have been sentenced for a "sickening" acid attack which left a man with horrific burns.

Wayne Ingold, 57, was not the intended victim of the attack, which happened outside his block of flats in Witham, Essex on 8 August 2014.
Aarron Isaac, 19, of Elverson Road, Lewisham and Jake McCabe, 16, also from London, had denied any involvement.
Isaac has been jailed for five years, while McCabe must spend three years in detention.
After serving their prison sentences, the pair will spend a further five years and three years respectively on licence.
The jury at Chelmsford Crown Court found them guilty of throwing a corrosive liquid with intent to cause grievous bodily harm after a week-long trial in October.
During the trial, Mr Ingold said he had been checking the post box in the communal entrance at his home when he saw figures moving outside.
When he opened the door, the teenagers had a glass bottle full of liquid which they threw over him before running off.
"It [the acid] hit my hands, my face, my neck. I went into my flat and looked in the mirror. My face had turned yellow. It looked like melted wax," Mr Ingold told the court.
Prosecutor Martin Mulgrew said Mr Ingold had been the victim of mistaken identity.
Speaking to BBC Essex after the sentencing, Wayne Ingold said: "I'm scarred for life because of what they've done to me.
"I was led to believe they would probably get lengthier sentences, but, now I've calmed down, I suppose 10 and six years isn't too bad.
"The only reason the younger lad got six years was because he has written a letter of apology to me admitting he did it to me."
Mr Ingold said McCabe claimed his family were threatened by drug-dealers and he was made to carry out the attack.
"If he'd admitted it in the first place, none of this would have carried on as it has done," he said.
"He wants to know if, in time, I will forgive him, which is sad in many ways, but, at the moment, can I forgive? No.
"Maybe in time I probably might do. I don't know. I've been through 14 months of hell because of them two.
"I'm scarred for life because of what they've done to me.
"I'm a fighter and I'll bounce back - you have to otherwise they've beaten you.
"But it's been hard and they might have to operate on my shoulder again."
Det Sgt Becky Young, of Essex Police, said: "He will not only be dealing with the physical scars but also the mental scars for a long time to come."


The jury in the trial of a man accused of murdering an imam has retired to consider its verdict.

Jalal Uddin, 71, died after suffering head injuries in an attack in a children's play area in Rochdale.
Mohammed Hussain Syeedy, 21, of Ramsay Street, Rochdale, denies murder and being the getaway driver for Mohammed Kadir, 24, who is alleged to have killed Mr Uddin, in February.
Manchester Crown Court has heard claims they hated the imam's form of Islam.
The prosecution alleged they believed Mr Uddin was performing "black magic" because of his practising of Ruqya healing, which involves the use of amulets known as taweez.
It was also claimed they supported the so-called Islamic State (IS) and sought to punish the imam with death for this practice, in line with the group's beliefs.
Mr Syeedy, a former Manchester United steward, admitted he disagreed with Mr Uddin's beliefs but denied any link to IS.
He also told the court he did not suspect Mr Kadir of planning or being involved in the imam's murder.
Mr Kadir, of Chamber Road, Oldham, boarded a flight to Denmark three days after Mr Uddin's death on 18 February, followed by a connecting flight to Istanbul.
His whereabouts are unknown, although it is thought he may have travelled to Syria.


Life-sized sculptures by Antony Gormley have been placed at five beauty spots around the UK that were specially selected by the artist.

Each cast-iron sculpture was designed to complement its surroundings, with all five beside water, including the North Sea and English Channel.
The commission - entitled Land - was created to mark 50 years of UK building conservation charity Landmark Trust.
Gormley said the artworks were "catalysts for reflection".
The sculptures were designed to engage with the elemental conditions of the Kilbrannan Sound, Bristol Channel, North Sea and English Channel.
The fifth location is a quiet site in a Warwickshire village, where the sculpture stands looking into the depths of a man-made lock.
The five locations for the Land sculptures are:
The figures will remain in place until May 2016.
Sir Antony said: "I am excited about making sculpture that stands in the wind, the rain and snow, day and night.
"The sculptures will be like standing stones: Markers in space and time, linking with specific places and their histories."
Landmark Trust historian Caroline Stanford said: "For our 50th anniversary, we wanted to do something that everyone can enjoy, not only for those that stay in our buildings but the local communities in whose landscape the local buildings fit."


One woman has died and at least 31 others have been hospitalised after a security exercise at a university in the Kenyan capital Nairobi.

Staff member Esther Kidemba died from severe head injuries, Strathmore University confirmed in a statement.
Panic spread after security officials fired gunshots as part of the drill at midday on Monday, local media report.
Several students said they had not been given advance warning of the security exercise.
Most of the injuries were caused by people jumping from windows, a medical source told AFP news agency.
"We were not informed... we just heard gunshots and had to run for our dear lives," one student told the local Capital FM news website.
Strathmore University said in an official statement that the drill had been carried out to test "the preparedness of the university community and emergency team in the event of an attack".
It added that teams of students and staff had been trained in "evacuation, assembly points and exit points", but did not elaborate on whether people had been notified about the timing of the drill.
"Unfortunately some students and staff panicked and got injured," it said in a statement released before the news of Ms Kidemba's death was confirmed.
Many Kenyans have taken to social media to condemn the university over the apparent mishandling of the exercise and for putting the lives of students and staff at risk.
"What happened today at Strathmore University was an attack, not a drill!," commented one twitter user.
The university has said it will cover the medical costs of those injured as a result of the exercise.
Nairobi police chief Japheth Koome said all the proper procedures were followed for Monday's drill, Reuters news agency reports.
In April. the Kenyan government instructed the country's higher education institutions to provide training to teach students how to respond in the event of a terror attack.
It followed the killing of at least 148 people, mainly students, in an attack by Islamist militant group al-Shabab on Garissa University College in north-eastern Kenya.


Saudi-led coalition aircraft have dropped leaflets warning residents in a Yemeni border district to leave, as air strikes against Houthi rebels continue.

Leaflets were dropped in Old Saada in Saada province, the rebels' stronghold.
Houthi rebels have fired shells from Saada into Saudi Arabia in recent days, killing 10 people.
But the NGO Medecins sans Frontieres, which has a team in Saada, warned people would not be able to leave the city quickly because of fuel shortages.
Saudi Arabia says the offensive aims to restore Yemen's exiled president.
The spokesman for the Saudi-led coalition, Brig Gen Ahmad Assiri, said Yemenis were being advised to stay away from Houthi strongholds for their own safety.
Mr Assiri said the overnight air strikes in Saada province were aimed at those behind the attacks on Saudi territory.
"Our work now is reaching those [Houthis] who planned these attacks and who are hiding in Saada, and the places where the militias are," Gen Assiri told Saudi TV.
The latest strikes hit Houthi command-and-control centres, said the Saudi state news agency SPA. Residents said the tomb of the Houthi movement's founder, Hussein al-Houthi, was also hit.
Earlier, Gen Assiri warned of "harsh" retaliation for a cross-border shelling attack by the rebels on the Saudi city of Najran on Wednesday.
But MSF said it had five staff working in a hospital in Saada, and urged Saudi Arabia not to attack the city.
Llanos Ortiz, an emergency co-ordinator with the NGO in the neighbouring Hajjah province, said: "It is impossible for the entire population of Saada province to leave within hours.
"Many people have no transport or fuel due to the coalition's blockade. Many others have no access to information as the province's phone networks are barely operational.
"If the coalition goes ahead with the threat of massively bombing the province, many people will die under the bombs."
At a meeting in Paris on Friday, Saudi Foreign Minister Adel al-Jubeir said a five-day humanitarian ceasefire would start at 23:00 local time (20:00 GMT) on 12 May.
A letter signed by 22 charities on Thursday called instead for a permanent end to the fighting.
A senior Houthi official, Mohamed al-Bukhaiti, told BBC Arabic on Friday that the ceasefire had not been formally proposed and the Houthis would not respond until a plan was properly laid out.
Air strikes have killed at least 1,200 people, more than half civilians, the UN says.
The crisis began when Shia Houthi rebels from the north, backed by forces loyal to Yemen's former president, took over the capital Sanaa late last year, and have since expanded their control.
Sunni Muslim Saudi Arabia has accused Shia rival Iran of arming the Houthis, a charge Iran and the Houthis deny.
The Saudis have been sheltering the internationally recognised Yemeni President Mansour Abdrabbuh Hadi, who fled there in March.


Motherwell have signed central defender Cedric Kipre on a one-year deal.

The 20-year-old Frenchman had been on trial with the Fir Park club following his release from Leicester City.
He is the eighth new arrival for manager Stephen Robinson, who says he is still looking for another defender and a striker.
"He's only 20 years old but his development is staggering, he is incredibly strong," said Robinson of Kipre.
Leicester paid £70,000 to take Kipre from Paris St-Germain in 2014.
"I managed to get a very good look at him over the past few weeks and it was never a doubt in my mind that we'd offer him a contract," Robinson told the club website.
Find all the latest football transfers on our dedicated page.


Oil giant Shell has been fined £22,500 after a leak at a North Sea platform in 2011.

It involved the Gannet Alpha platform, 113 miles (180km) from Aberdeen.
The pipeline involved - which leaked more than 200 tonnes of oil - was about 300ft (91m) below the surface.
Shell admitted two charges relating to the incident at Aberdeen Sheriff Court. The BBC Scotland news website revealed last week the firm had been charged over the incident.
The court heard Shell's overall costs arising from this incident were estimated at about £45m, and the cost of replacing the pipeline was about £100m.
Paul Goodfellow, Shell's upstream director for the UK and Ireland, said: "We deeply regret the Gannet spill and accept the fine which has been handed down to us.
"We know that no spill is acceptable. Safety is at the heart of our operations and following this incident, a comprehensive review of our North Sea pipeline system was conducted.
"We have learnt lessons from this review and have applied them across our UK upstream operations."
WWF Scotland director Lang Banks said: "Despite being responsible for worst North Sea spill in a decade, the level of the fine is literally a drop in the ocean when compared to the billions earned by Shell annually.
"When it comes to protecting the marine environment and its own employees it's absolutely right that oil companies are prosecuted for their mistakes and that lessons are also learned by the wider industry.
"It's therefore disappointing that the fine was not much larger in this case."
Shell deployed a remotely operated vehicle to find the leak in the pipe flowing between an oil well and the platform.
The company shut off the well and depressurised the pipeline, stemming the flow of oil.
Work to release gas trapped in the pipeline was completed in November 2011.


Lewis Hamilton produced a stunning lap to set pole position at the Canadian Grand Prix and equal his hero Ayrton Senna with the 65th of his career.

Hamilton ended the session 0.330 seconds quicker than title rival Sebastian Vettel of Ferrari.
The Briton produced a series of blistering laps on a track where he has won five times in nine races.
As a result of his latest performance, he is just three poles behind all-time holder Michael Schumacher.
After the session, Hamilton was presented with one of Senna's old helmets, a gift from the late Brazilian's family for equalling his record.
"Wow," he said, dropping his driving gloves in amazement. "I'm shaking. Ayrton, I know for many of you was your favourite driver and he was for me. He inspired me to be where I am today so to receive this is the greatest honour."
Hamilton, who is 25 points behind Vettel in the championship after finishing seventh in Monaco, was clearly elated following the session, in which he showed a superiority that was completely unexpected.
Ferrari and Mercedes have been closely matched all weekend but Hamilton was in a league of his own once the top 10 shootout started.
It was a gripping climax to qualifying. Hamilton produced a blistering lap of one minute 11.791 seconds, only for Vettel to set a time just 0.004secs slower than him.
But Hamilton saved his best for last, lowering his time to 1:11.459, while Vettel did not improve.
"I am so happy," Hamilton added. "Montreal has been good to me over the years. It was a close battle with the Ferraris, who have been so quick all year. I just wanted a good lap, and I got it.
"It was a sexy lap, a great lap. I can't believe it came together so well.
"The team did a great job to learn from our mistakes in the last race and I really owe it all to them."
Vettel said: "I think we have the pace (to win). I was not so happy with the last lap but it was a good qualifying session."
Hamilton's team-mate Valtteri Bottas was third ahead of Ferrari's Kimi Raikkonen.
The three-time champion and Vettel were each half a second quicker than their respective team-mates.
Red Bull were best of the rest, as ever, Max Verstappen pipping team-mate Daniel Ricciardo for fifth place, with Williams' Felipe Massa seventh ahead of the Force Indias of Sergio Perez and Esteban Ocon, and Nico Hulkenberg's Renault.
The German's team-mate Jolyon Palmer, whose future at the team is in doubt, was down in 15th after being 0.7secs slower in second qualifying.
Fernando Alonso was 12th on his return to Formula 1 after missing the Monaco Grand Prix to race in the Indianapolis 500, well ahead of team-mate Stoffel Vandoorne in 16th.
Canadian rookie Lance Stroll struggled at his first home race, the 18-year-old 0.7secs off Massa in first qualifying and qualifying 17th.


Scientists in the US have unveiled an athletic robot which takes its inspiration from bush babies.

Salto the robot can perform multiple vertical jumps in a row - making it a champion robot athlete.
Bush babies, or galagos, can jump five times in four seconds, to reach a combined height of 8.5m.
Writing in Science Robotics, the researchers say the prototype could be used for search and rescue in disaster zones.
The bush baby (Galago senegalensis) is a nocturnal primate native to Africa. It has the unusual ability to store energy in its tendons, enabling it to jump to heights not achievable by its muscles alone.
Duncan Haldane and his colleagues at the University of California, Berkeley, describe the bush baby's special skill as "vertical jumping agility".
To compare robots and animals, the roboticists developed a new metric to measure vertical agility.
This is defined as the height something can reach with a single jump in Earth gravity, multiplied by the frequency with which that jump can be made.
Their robot is 26cm tall and weighs 100g. A motor drives a spring, which loads via a leg mechanism to create the kind of crouch seen in the bush baby.
Salto mimics the way energy is stored in the tendons of the nocturnal mammal, which means it doesn't need to wind up before a jump. As soon as it leaps, the robot is ready to go again.
With a vertical jumping agility of 1.75 metres per second (m/s), Salto was able to achieve 78% of the bush baby's score; the mammal has a jumping agility of 2.24 m/s.
However, the Californian-built robot was able to beat a bullfrog on the same metric.
"By combining biologically inspired design principles with improved engineering technology, matching the agile performance of animals may not be that far off," said co-author Prof Ronald Fearing.
The research has been backed by the US Army Research Laboratory among other funders.
Follow Paul on Twitter.


A woman has been arrested in connection with an alleged attempted murder in the Maryhill area of Glasgow.

A 30-year-old man is being treated for serious injuries at Glasgow Royal Infirmary following the incident in Hathaway Lane at 20:25 on Saturday.
Officers said the incident involved up to 10 people.
Police said a 41-year-old woman was being detained in police custody and a report would be submitted to the procurator fiscal.


Union leaders have held talks with MPs over a plan they claim could end the long-running row on Southern rail.

The company has been in dispute for more than a year with the RMT over changes to guards' roles on trains.
RMT conductors saw the changes as a ploy to phase out a second person on trains. It has now proposed a six-month trial with two staff guaranteed on all affected services.
But Southern said what the RMT wanted was "a guarantee to cancel trains".
Under the changes to guards' roles, which were also opposed by the Aslef train drivers' union, responsibility for opening and closing doors passes to the driver rather than the conductor.
The practice is called driver-only-operation (DOO).
Southern rail strike: What's it about?
RMT leaders have set out an "accessibility guarantee" plan, which would ensure a driver and an on-board supervisor staff all trains.
This would mean disabled, elderly and vulnerable passengers would be provided with guaranteed assistance from on-board staff on all services without the need to book in advance, the union said.
RMT general secretary Mick Cash said: "We are hoping the company will reconsider our proposal for a trial six-month period of an accessibility guarantee.
"We would hope that they would agree to this sensible proposal as the Association of Train Operating Companies consultant's report has said train companies should guarantee a second person to comply with their legal obligations."
But a spokesman for Southern said: "The guarantee the RMT wants is a guarantee to cancel trains. We want to put the passenger first and keep trains running.
"Driver-controlled operation is safe and provision for those who need assistance has not deteriorated while, at the same time, service levels have steadily improved."
RMT members on Southern will stage a fresh strike next Monday, while Aslef has banned overtime.


The numbers arriving in accident and emergency units have surged.

Calls to the NHS 111 helpline have been a lot higher than the same time last year. Yet the weather has not been unusual for winter and norovirus and flu numbers are nothing out of the ordinary.
So what's going on? Nobody, it seems, has a very clear answer.
The weekly NHS England figures (ending 24 January) reveal an 8% year-on-year increase in attendances at major A&E units.
Calls to 111 were 20% higher than the same week last year.
A Welsh government spokesman said there had been a sharp rise in the number of people seeking treatment in emergency departments.
It seems to have been a similar picture in Scotland, though with some improvement on last winter according to its government.
This week the pressures don't seem to have eased, though we don't yet have the detailed data. There were reports of an "extremely serious situation" at one hospital which had to cancel all routine operations and appointments, apart from cancer surgery, for two days.
GPs in north London were told that two local hospitals were experiencing "very high pressure on beds" which created a "significant challenge to safe operating". Practices were asked to consider using alternative options for their patients including walk-in centres.
It adds up to a service under even greater pressure than most had expected. NHS England noted there had been bad weather last week, which might have accounted for some of the increase in patient numbers.
But while paying tribute to the "remarkable" job done by staff in providing high quality services, NHS chiefs acknowledged the "very real" pressures which were not expected to ease in the run-up to spring.
Heads of emergency departments point out there has not been a sudden new spike in numbers of people coming through their doors. They argue that there has been a steadily increasing trend going back a couple of years.
Familiar factors are quoted, including numbers of frail, elderly patients with multiple conditions needing an increasing range of care and treatment.
One specialist in geriatric medicine told me more older patients were coming into A&E because of problems with care in their home. This could be because social care was lacking in some way, or because a spouse had become unable to cope.
But the surge in hospital attendances was by no means dominated by the over-65s.
One theory being put forward is that A&E is a well-regarded "brand" amongst the public and is trusted to deliver high quality care even with a wait.
This could tie in with people feeling that their local GP practice is overburdened and a perception that appointments are not easy to get. In a 24/7 culture people increasingly expect instant service, including from the NHS.
Winters are always busy in the NHS and there are always difficult weeks. This one is unusual because of the scale of the increase in demand.
If one thing is clear, it is that people are not getting the message to avoid A&E and go elsewhere unless it's a genuine emergency.
Special report page: For the latest news, analysis and video
Winter across the UK:  A guide to how the NHS is coping
Video: Why hospitals are under so much pressure
Video: How a hospital can grind to a halt


Sir Andy Murray will face defending champion Novak Djokovic in the Qatar Open final on Saturday after beating third seed Tomas Berdych in the semis.

Murray won 6-3 6-4 against Czech Berdych, who needed treatment on an ankle injury after the first set.
It will be the 19th ATP final meeting between Murray and the man he replaced as world number one in November.
Second seed Djokovic survived five match points on his way to beating Fernando Verdasco in his semi-final.
Spaniard Verdasco, ranked 42nd in the world, controlled the first two sets but Serb Djokovic made only one unforced error in the decider to win 4-6, 7-6 (9-7), 6-3.
"It's definitely one of the most exciting matches I have played," Djokovic said. "I haven't saved five match points many times. He should have finished it off."
You can follow to live coverage of the Qatar Open final in Doha between Murray and Djokovic on the BBC Sport website from 15:00 GMT.


Ed Miliband has visited Scotland the day after appearing to rule out a deal with the SNP - even it meant putting the Conservatives in power.

His Scottish trip came after SNP leader Nicola Sturgeon said Scottish voters would never forgive Labour if it allowed the Conservatives back.
The Tories said Mr Miliband's claim "changes nothing".
The Liberal Democrats have claimed the SNP views the election as a stepping stone to another independence vote.
Labour leader Mr Miliband said during a special BBC Question Time programme on Thursday evening that a Labour government is "not going to happen" if the price of power was doing a deal with the SNP.
He added: "I'm not going to sacrifice the future of our country, the unity of our country, I'm not going to give in to SNP demands around Trident, around the deficit or anything like that."
Mr Miliband has come under sustained pressure from the Conservatives throughout the election campaign over the prospect of a Labour-SNP deal in the event of a hung parliament.
Ms Sturgeon faced questions from a studio audience on BBC Scotland following Mr Miliband's appearance on Question Time.
She said: "I heard Ed Miliband and he sounded awfully like he was saying, and I hope that I am wrong about this because I think people across Scotland and much of the UK will be appalled if I am right, he sounded as if he was saying that he would rather see David Cameron and the Conservatives back in government than actually work with the SNP.
"Now, if he means that then I don't think people in Scotland will ever forgive Labour for allowing the Conservatives back into office."
Polls have suggested Labour is facing the prospect of a heavy defeat in its former Scottish stronghold, with the SNP on course to win the vast majority of seats.
During the Labour rally in Glasgow, Mr Miliband evoked the names of Labour's Scottish founder Keir Hardie and the architects of devolution John Smith and Donald Dewar, and ask Scots who their parents and grandparents would want to lead the country.
He urged voters in Scotland not to "gamble" on the SNP and insisted "you can guarantee change with Labour".
He said his opposition to any post-election deal with Nicola Sturgeon's SNP is for "principled reasons", adding: "We cannot do a deal with a party that wants to break up the UK when we want to build it up."
Mr Miliband said the UK "could be on the verge of electing a Labour government", and added: "Nationalism never built a school. It never lifted people out of poverty. It never created a welfare state that healed the sick and protected our most vulnerable.
Ms Sturgeon has made campaign stops in East Lothian, Dundee and Fife as she takes the SNP's message to communities around the country.
Speaking on BBC Radio 4's World at One, the SNP leader said: "The SNP is not going into Westminster to bring down governments or to stop budgets getting through.
"We would be going to try to get more progressive policies from a minority Labour government."
Elsewhere, Scottish Conservative leader Ruth Davidson joined Borders candidate John Lamont at a rally followed by a street stall event in Galashiels.
Ms Davidson said on Thursday that the choice facing voters in next Thursday's election was between "a party which will keep Scotland's economy strong and keep Scotland in the UK and a weak Labour government haggling with the SNP over how to run the UK".
Speaking in Leeds about Mr Miliband's assertion, Prime Minister Cameron said: "Is he really saying that if Labour don't get a majority but if Labour plus the SNP is a majority 'I won't be PM'? Of course he's not saying that.
"The threat today is the same as the threat yesterday. Ed Miliband propped up by the SNP not governing on behalf of the whole country."
Meanwhile, Scottish Lib Dem leader Willie Rennie met therapy animals as he revealed plans to boost mental health services.
Mr Rennie visited volunteers from Canine Concern in Edinburgh. The group's Therapet programme brings together pet owners with individuals struggling with mental or physical ill health.
Mr Rennie said his party would use their planned Â£800m investment in the NHS in Scotland to rebalance support between physical and mental health services.
On potential post-election deals, he said the voters faced a choice between a government influenced by UKIP's Nigel Farage, the SNP's Alex Salmond or the Liberal Democrats.
Mr Rennie insisted the Lib Dems would hold politics in the centre ground and help keep the economy on track fairly, and said Scotland needed to focus on the issues that mattered rather than a second independence referendum.
What are the top issues for each political party at the 2015 general election?
Policy guide: Where the parties stand


It's been another tough day for Twitter as its quarterly earnings report, once again, sends its stock price spiralling downwards.

The social network is struggling on several fronts. In New York, Wall Street investors and analysts are perpetually unimpressed.
And online, social media users are becoming increasingly uninterested as Twitter is dwarfed by Instagram, Snapchat, WhatsApp and others.
Is there any hope of reversing the decline? Surely, for a platform that boasts world leaders, sports superstars and even Jesus himself (unverified) among its members, there must be some way to find a bright future for Twitter and its bank balance?
Here's what it needs to do to please both investors and users.
Michelle Fleury, BBC Business Reporter, New York
To quote the film Jerry Maguire, "show me the money". Or at least the new users.
That's what Wall Street wants to see.
Twitter shares tanked - falling as much as 10% in after hours trading. Not because its financial performance was terrible but because the company that invented the 140-character tweet failed to add enough new users.
In the last three months, Twitter gained four million new users. Although that is up 11% from a year earlier, the 320 million monthly active users were still short of the 324 million forecast by many analysts here.
It's not a great start for Jack Dorsey, who was confirmed as chief executive earlier this month.
For investors, the number of users and how fast that figure is growing is a measure not just of Twitter's health today, but of its prospects for the future.
Last quarter, when he returned to the helm, Mr Dorsey sent Twitter shares lower after saying that he was not satisfied with user growth and that the product was too complicated to use.
Since then Mr Dorsey, who also runs payments company Square, has set about trying to fix this problem.
Earlier this month he slashed 8% of Twitter's workforce. Almost at the same time, Twitter rolled out Moments, a service that collects tweets and links about noteworthy news events.
And more recently, Twitter released a polling tool that allows users to tweet a poll with two choices.
Mr Dorsey's attempts to revitalise the company he co-founded may only just have begun, but he will have to do a lot more to persuade investors that user growth is just around the corner.
Follow Michelle Fluery on Twitter @BizFleury
Dave Lee, BBC North America technology reporter, San Francisco
During his conference call with investors, Jack Dorsey cited a punishing statistic about Twitter.
In its target markets - the Western world, basically - Twitter has around 90% brand recognition among the general population. Which figures, it's a household name and a brand that is uttered constantly in the media.
But despite that awareness, it often has less than 30% penetration in those same areas. As in, even though lots of people know about Twitter, few of them are bothering to sign up and get involved.
Why? Mr Dorsey thinks it's too complicated for people to understand. To combat this he's instructed his team to work on tools that make things easier. The flagship feature for this way of thinking is Moments, which gathers tweets based not on who you follow, but what events you are interested in.
"Our products need to change in a fundamental way to attract that next cohort [of users]," Mr Dorsey told investors.
But that will be extremely difficult. Mr Dorsey essentially has to conceive and build the next Twitter, while at the same time not dismantling current Twitter.
The task is even more enormous when you consider very few of the key traits that made Twitter popular were even invented by the company in the first place.
Hashtags? Invented by a user. Retweets? A user. Even the convention of using "@" to mention another Twitter came from a user, albeit sort-of accidentally.
When Mr Dorsey talks about Twitter's mission under his leadership it's one of simplicity and speed. Simple tools, released quickly.
In the pipeline, efforts to enhance Twitter as a place to interact with (and complain at) brands. And if you are a brand, tools that will allow you to monitor how your efforts on Twitter, be it ads or just presence, are performing.
Follow Dave Lee on Twitter @DaveLeeBBC


Deputy Prime Minister Nick Clegg faces a "tough gig" debating UK membership of the European Union with UK Independence Party leader Nigel Farage, a fellow Lib Dem minister has warned.

But Simon Hughes said Mr Clegg was "hugely qualified" for the job.
On Friday, Mr Farage accepted the Lib Dem leader's offer of a debate, saying he could "hardly wait".
But Conservative former Deputy Prime Minister Lord Heseltine described Mr Clegg's challenge as "a misjudgement".
In his weekly phone-in show on LBC radio last week, Mr Clegg described the Lib Dems as the "party of 'in'", meaning it was the most pro-European of the major parties at Westminster.
He challenged Mr Farage, support for whose anti-EU-membership UKIP has surged in recent opinion polls, to a "public, open debate".
Mr Farage accepted, saying it was "the most important issue this country has faced for hundreds of years".
Speaking on BBC One's Andrew Marr Show, Justice Minister Mr Hughes said: "Of all the people that's equipped to know the history and the workings of the EU and its benefits, and has also had to argue this case lately, I think Nick is hugely well-qualified.
"He can speak as a solid Brit who understands the benefits. I think it will be great television."
Mr Hughes added: "It will be a tough gig and he knows that and Nigel is a difficult opponent but Nick has never been afraid. He wouldn't be in government with the Tories if he was afraid of tough gigs."
But Lord Heseltine, who is a pro-European, told Sky News that Mr Clegg should not publicly take on Mr Farage.
He said: "I wouldn't do it if I was him (Mr Clegg). I think that it's a misjudgement frankly to equate the leadership of a party which is part of government with a protest group, particularly a protest group which frankly is more about immigration than it is about Europe."
He said opponents of UKIP should stop "talking about the United Kingdom Independence Party and start talking about the United Kingdom isolationist party".
Prime Minister David Cameron has promised, if the Conservatives win the 2015 general election, to hold an in/out referendum on the UK's EU membership by the end of 2017.
This, Mr Cameron says, would follow a full renegotiation of relations with Brussels.
Speaking on the Andrew Marr Show, Foreign Secretary William Hague said the EU had to show more "flexibility".
Ahead of a visit to the UK later this week by German Chancellor Angela Merkel, he described Germany as the "most important partner" on seeking reform because of its economic strength and key role in the eurozone.
Mrs Merkel will address both Houses of Parliament on Thursday, and Mr Cameron is expected to raise the issue of overhauling the EU's immigration rules to deal with "benefit tourism".
Mr Hague said: "We support the principle of the free movement of workers, and many British people have rightly taken advantage of that in the rest of Europe.
"But we don't support people moving from one country to another because of the incentives of different benefit systems."


Drug cheats in sport face a minimum four-year ban under new rules which came into effect from 1 January.

Changes to the World Anti-Doping Code, which unifies anti-doping rules for global sports, have increased the suspension for doping from two years.
Other changes will see less leniency given for missed tests but possible reduced bans for helping investigators.
UK sports minister Helen Grant said the changes would "better protect clean athletes around the world".
"Successful implementation will mean an innovative and robust anti-doping programme that reaches further than ever before, to more athletes, more support personnel and more sport lovers, all of who want to be part of sport free from doping," she added in a statement via UK Anti-Doping.
"We will see tougher sanctions - not just for athletes, but also for those who assist in the doping process."
The punishment for missing three tests within a 12-month period has been increased from 18 months to two years.
While deliberate cheating leads to a four-year ban, athletes guilty of "inadvertent doping" will receive a two-year ban - although they can get a reduction if they have "substantial proof that they were not at fault or intending to cheat".
Wada said the 2015 code had more incentive for anyone providing "substantial assistance" in uncovering doping.
"Admitting a violation can be rewarded with a reduced ban, with Wada having the final say. In exceptional cases, Wada has the power to eliminate a ban entirely and offer complete confidentiality for substantial assistance," it said.
The revised code was agreed by the World Anti-Doping Agency (Wada) in November after over 18 months of research by the governing body.


Lucian Freud, one of Britain's most distinguished and highly regarded artists, who has died aged 88, was once described by art critic Robert Hughes as the greatest living realist painter.

A grandson of the psycho-analyst Sigmund Freud and the son of an architect, Lucian Freud was born in Berlin in 1922 and fled from Nazi Germany to Britain with his Jewish family in 1933, when he was 10. His younger brother was Clement Freud, who went on to become a broadcaster and writer.
In his mid-teens he went to art school in London and then to another in East Anglia and he became a British citizen in 1939.
At first he confined himself to drawing, and when he was 17 had a self-portrait accepted for reproduction in Cyril Connolly's magazine, Horizon.
He later characterised his early work as the product of "maximum observation", achieved "by staring at my subject matter and examining it closely".
Freud was recognised as a brilliant talent and, after a spell in the Merchant Navy in 1942, had his first one-man show in 1944, when he was 21.
He had begun painting in the early 1940s and after the war went to France and Greece, before returning to Britain in 1948 to teach for 10 years at the Slade School of Art. By then he was working more with oils.
Lucian Freud's portraits were not concerned with flattery or modesty - disturbing was one adjective applied to them - and some were said to have compelling nastiness.
The Freud paintings we all own
Though sometimes startling, his portraits could also be beautiful and intimate. Freud had been an admirer of the artist Francis Bacon and painted a striking portrait of him.
Freud, who lived and worked in London, said his work was purely autobiographical - he painted "the people that interest me and that I care about and think about in rooms I live in and know".
A close relationship with sitters was important to him. He painted several affectionate portraits of his mother and his daughters Bella and Esther were also models.
Sittings could last for a year and sitters were often profoundly affected by the process. One of them once said: "You are the centre of his world while he paints you. But then he moves on to someone else."
Freud seldom accepted commissions. His work is in a number of galleries in Britain and overseas, but much of it is privately owned.
He was one of few artists to have had two retrospective exhibitions at the Hayward Gallery in London.
Freud was married twice: his first wife was sculptor Jacob Epstein's daughter, Kitty, the subject of his celebrated Girl With a White Dog. His second wife was the daughter of the Marquess of Dufferin and Ava.
Although Freud, who was made a Companion of Honour in 1983, had a reputation as a great womaniser and a reckless gambler, he was a private person, gave few interviews, and would not have a telephone in his studio.
His love of animals was demonstrated in 2010 when he was tempted out of seclusion for the short film "'Small Gestures" by the prospect of being filmed with a kestrel and a zebra.
He had vowed never to give up working, stating that he intended to paint himself to death.


Luke Donald shot a six-under-par 65 to be tied second after day one of the PGA Tour's RBC Heritage in South Carolina.

The world number 96 carded five birdies, an eagle and dropped just one shot to join Canada's Graham de Laet and American Sam Saunders in second.
American Bud Cauley leads on eight under, dropping no shots in his round.
England's Ian Poulter produced one of the lowest rounds of his season to reach five under, with Ireland's Shane Lowry tied fourth on the same mark.
Danny Willett - who missed the cut as defending champion at the Masters last week - described his level-par start as "steady".
Englishman Donald - who was world number one in 2011 - last won on the Japan Tour in 2013, with his most recent PGA Tour victory arriving at the Transitions Championship in March 2012.
But he has finished second at this event - held at Harbour Town Golf Links - four times in the past eight years.
The 39-year-old started the day on the back nine but after turning in three under, produced an eagle on the second hole when his 209-yard approach left a short putt.
Cauley, 27, sat out all of the 2015 season after shoulder surgery and has missed the cut on his last two outings.
But he needed just one putt on each of the last three holes to convert successive birdies and in doing so secured a two-shot lead going into Friday's second round.
Last year's winner Branden Grace is tied for 19th on two under.


Sammie Szmodics struck a late equaliser to earn Colchester a draw at Cambridge in League Two.

Substitute Szmodics turned the ball home from close range six minutes from time after good work on the left by Ben Dickenson, moments after Macauley Bonne had seen a goal disallowed for offside following another Dickenson cross.
Gerry McDonagh had earlier scored his first EFL goal to give the home side the lead after 20 minutes, thumping the ball in following George Maris' pass from the right.
Cambridge also had a goal disallowed when Harrison Dunk fired in following Piero Mingoia's cross 11 minutes before half-time.
Colchester's only real opportunity of the first period came in the opening moments when Dickenson could only nod Owen Garvan's cross wide at the far post.
John McGreal's side were denied 17 minutes from the end as a superb save from Will Norris kept out George Elokobi, before McDonagh fired narrowly wide at the other end ahead of Szmodics' equaliser.
Match report supplied by the Press Association.
Match ends, Cambridge United 1, Colchester United 1.
Second Half ends, Cambridge United 1, Colchester United 1.
Foul by Scott Wharton (Cambridge United).
Macauley Bonne (Colchester United) wins a free kick on the right wing.
Attempt missed. Tom Lapslie (Colchester United) right footed shot from outside the box is close, but misses the top right corner.
Leon Davies (Cambridge United) is shown the yellow card for a bad foul.
Foul by Leon Davies (Cambridge United).
Brennan Dickenson (Colchester United) wins a free kick in the defensive half.
Foul by Liam O'Neil (Cambridge United).
Drey Wright (Colchester United) wins a free kick in the attacking half.
Substitution, Cambridge United. Medy Elito replaces George Maris.
Goal!  Cambridge United 1, Colchester United 1. Sammie Szmodics (Colchester United) header from the centre of the box to the bottom right corner. Assisted by Brennan Dickenson with a cross.
Attempt missed. George Maris (Cambridge United) right footed shot from outside the box is close, but misses to the right.
Substitution, Colchester United. Macauley Bonne replaces Chris Porter.
Attempt missed. Scott Wharton (Cambridge United) header from the centre of the box is close, but misses to the left following a set piece situation.
Piero Mingoia (Cambridge United) wins a free kick in the defensive half.
Foul by Tom Lapslie (Colchester United).
Attempt missed. Gerry McDonagh (Cambridge United) left footed shot from the left side of the box is close, but misses to the right.
Corner,  Cambridge United. Conceded by Matthew Briggs.
Substitution, Colchester United. Sammie Szmodics replaces Sean Murray.
Substitution, Cambridge United. Leon Davies replaces Greg Taylor.
Attempt saved. Gerry McDonagh (Cambridge United) right footed shot from the centre of the box is saved in the bottom right corner.
Attempt saved. George Elokobi (Colchester United) left footed shot from the left side of the six yard box is saved in the bottom left corner.
Corner,  Colchester United. Conceded by Will Norris.
Foul by James Dunne (Cambridge United).
Tom Lapslie (Colchester United) wins a free kick in the defensive half.
Greg Taylor (Cambridge United) wins a free kick in the attacking half.
Foul by Rekeil Pyke (Colchester United).
Attempt saved. Luke Berry (Cambridge United) right footed shot from the left side of the six yard box is saved in the centre of the goal.
Foul by Scott Wharton (Cambridge United).
Sean Murray (Colchester United) wins a free kick on the right wing.
Substitution, Colchester United. Rekeil Pyke replaces Tarique Fosu-Henry.
Substitution, Cambridge United. James Dunne replaces Harrison Dunk.
Jake Carroll (Cambridge United) wins a free kick on the right wing.
Foul by Tarique Fosu-Henry (Colchester United).
Corner,  Cambridge United. Conceded by Drey Wright.
Attempt missed. Liam O'Neil (Cambridge United) right footed shot from outside the box is just a bit too high following a corner.
Corner,  Cambridge United. Conceded by Drey Wright.
Second Half begins Cambridge United 1, Colchester United 0.
First Half ends, Cambridge United 1, Colchester United 0.


Moray councillors have backed a 3% rise in council tax.

The increase adds £34.05 to a Band D property.
Local authorities can increase the basic rate of council tax by up to 3% for the first time since 2007, but higher-band properties will pay more regardless after MSPs approved changes.
This will see Band H properties in Moray pay £594.17 more.


The former chairman of UKIP in Scotland has been ordered to carry out 270 hours of unpaid work after admitting 10 sexual offences involving phone calls to women.

Arthur Misty Thackeray, 55, made the calls to 10 different women between October 2007 and December 2015.
Nine of the charges involved sending or directing "sexual verbal communication" and one was a breach of the peace.
Thackeray has been placed on the sex offenders register for three years.
Sheriff Martin Jones QC told him: "Be under no illusion, these offences you committed against these women are serious and caused distress."
Glasgow Sheriff Court was told none of Thackeray's victims knew him and it is thought he may have found their numbers on posters advertising slimming classes and, in one case, from an advert in a shop window.
The calls were made from Thackeray's home in Glasgow, from an address at 1 Colme Street in Edinburgh and from "elsewhere".
UKIP Scotland leader and MEP David Coburn's office is at the same address in Edinburgh.
Defence lawyer Callum Hiller said his client have given up drinking since the offences.
He added: "He now completely regrets his actions, he fully understands the significant distress his behaviour would have caused, if he could take it back he most certainly would."


Dublin side Cuala will be Slaughtneil's opponents in the All-Ireland Club Hurling semi-finals in February after they won the Leinster title on Sunday.

Cuala earned a 3-19 to 1-16 victory over Kilkenny club O'Loughlin Gaels at Portlaoise to lift the provincial title for the first time.
Con O'Callaghan, Colm Cronin and Mark Schutte hit Cuala's goals with free-taker David Treacy finishing with 0-11.
Danny Loughnane scored O'Loughlin Gael's second-half goal.
Cuala, who landed their first Dublin title in 2015, will be favourites in the All-Ireland semi-final against the Derry club on 4 February.
Slaughtneil clinched their first Ulster title in October after defeating 2012 All-Ireland champions Loughgiel 2-14 to 1-13 in the decider.


More than 10,000 crocodiles in Honduras that had gone hungry for weeks because their owners had their assets frozen were fed on Tuesday.

The crocodiles are bred for their skin and meat at a farm owned by members of the influential Rosenthal family.
The United States treasury department froze their assets last month over allegations of drug trafficking.
A Honduran firm donated two tonnes of cow entrails to feed the crocodiles and some lions which also live at the farm.
The US treasury on 7 October froze the assets of Jaime Rosenthal, his son Yani and nephew Yankel.
Yankel Rosenthal had been arrested the previous day at Miami airport.
US investigators accuse the three of money laundering and drug trafficking.
On Friday, the state-run Forest Conservation Institute donated 1,500kg (3,000lb) of chicken to the farm after news emerged that the animals had not been fed since the Rosenthals' assets were frozen.
But local media reported that the farm's employees refused to feed the animals until their wages had been paid.
The Forest Conservation Institute said it would find a way to reach an agreement with the workers.
On Tuesday it announced that a local firm which regularly supplied the crocodile farm had donated two tonnes of cow entrails and that both the entrails and the chicken had been fed to the animals.
The farm's manager said the food would last for "two to three days".
About 11,000 crocodiles and seven lions live at the 30-hectare farm.
As well as the crocodile farm, the family owns a newspaper, a football club and a bank.
The bank, Banco Continental, is being liquidated, and the newspaper, Tiempo, has not been published since last week.
The Rosenthals have played key roles in Honduran politics for decades.
Jaime Rosenthal, 79, served as the country's vice-president from 1986 to 1990 and ran for president on a number of occasions.
Yani Rosenthal, who also had presidential aspirations, was a government minister from 2006 to 2009. Yankel is also a former minister and owns one of Honduras' most famous football clubs.


Celtic assistant boss John Collins has confirmed he will be leaving the club along with manager Ronny Deila at the end of the season.

The Norwegian announced on 20 April he would depart, before a fifth straight Scottish title was secured on Sunday.
"I came with Ronny, so it's only right I leave with him," said the former Scotland midfielder, who played for Celtic from 1990 to 1996.
"A new manager will come in and bring his own staff with him."
Collins said he will "go on some summer holidays and get some sunshine" before contemplating his next move, having helped Deila steer the club to successive titles in his two years back at Parkhead.
"It's disappointing to leave but a lot of people would be delighted to have what I've had," said the 48-year-old.
"I've played for the team and won a cup and two league titles as part of management. History will dictate whether it was good or bad.
"There have been lots of highs, some lows, but we've got five in a row.
"Of course, we all want better, we all want more. But we got the title, we got five in a row, so we pass the baton on to the next manager and see what he does."
Collins admitted that in the Champions League and Europa League, as well as their semi-final defeats by Ross County, in the League Cup, and Rangers in the Scottish Cup, Celtic "have not played as well as we could have. Ultimately, that has proved disappointing".
High expectations from supporters made for "constant challenges" at Celtic Park, he noted, but he believes they should still take pride in their run of Premiership titles.
"When you win, people can be unhappy, when you lose, people are really unhappy," he said. "There are big demands, but that's life at a big club.
"There are not too many clubs in Europe who have five in a row. We've got it and the target now is six."
Collins stressed it is now "absolutely vital" that Celtic act quickly to appoint replacements for Deila and himself.
"They can't get the next manager in quick enough," he added. "He has got to assess the squad and prepare for the Champions League games that come straight away.
"We have got lots of players away on international duty, so it is not an ideal scenario for the new manager to come into.
"We had it two years ago; not easy to manage. But you just have to deal with the situation as best you can, the quicker the better.
"But you can't rush decisions either. You have to take your time and [chief executive] Peter [Lawwell] and the board will take their time and get the right man."


Possible strike action could disrupt Caledonian Sleeper services between London and Scotland over Christmas.

Rail, Maritime and Transport union (RMT) members working for the service will be balloted next week over whether they want to take industrial action.
The union has said train defects have caused delays and cancellations.
Serco, which took over the running of the sleeper eight months ago, said it has been working hard to improve the service.
Members of the RMT will decide by 15 December whether to launch a campaign of industrial action.
The union said it had a "litany" of safety concerns which operators Serco had failed to act on.
The RMT said the service, which links Inverness and Fort William with London, had been suffering from defects such as broken toilets and fire alarms.
The union would have to give seven days notice of any action, raising the threat of a strike over Christmas.
Serco said it was disappointed that RMT members were considering strike action, but that it was committed to continued dialogue with staff.
It said it had worked hard to improve the service for customers and staff since it took over the franchise.


Thousands of Jordanians have attended a protest demanding political reforms in Amman, hours after King Abdullah called early parliamentary elections.

The Muslim Brotherhood's political wing, the Islamic Action Front, called for broader political representation and a more democratic parliament.
People at the protest chanted: "The people want to reform the regime."
On Thursday evening, the king dissolved parliament and called early elections, though he did not specify a date.
He has said he wants polls to be held by the end of the year.
The IAF said it expected 50,000 people to take part in the protest outside the capital's al-Husseini mosque after Friday prayers. But the BBC's Wyre Davies put the turnout at 10,000 people, which he said was the biggest protest seen in Jordan for several years.
Video footage showed protesters chanting slogans and waving flags. The AFP news agency quoted people as shouting: "We demand constitutional reform before the people revolt. The people want to reform the regime."
A counter-rally, in support of King Abdullah, which organisers had predicted would attract 200,000 supporters, was cancelled late on Thursday in order to prevent clashes between the two groups.
Earlier, police said they had detained eight people travelling towards the rally and had seized three vehicles containing sticks, knives and guns.
Friday's protest in the capital and the dissolution of parliament come amid mounting opposition anger at the electoral law passed in July by the government of the conservative Prime Minister Fayez al-Tarawneh.
The electoral law increased the number of seats in the House of Representatives from 120 to 150 seats and gave the electorate two votes - one for a district representative and one for national level lists that include political parties - replacing the single non-transferable vote.
The IAF's leader, Hamza Mansour, dismissed the legislation as "just a cosmetic change meant to buy time and insufficient for real reforms".
Opposition parties demanded that 50% of seats be allocated to party lists, but the new electoral law gave them just 27 seats, or 18%.
They also complained that the new law would strengthen supporters of the king by allocating three more seats for women from Bedouin districts.
This, they argued, would continue to marginalise Jordanians of Palestinian origin - who make up 60% of the population but have little political power - in favour of those descended from Jordan's original Bedouin inhabitants - whose tribes dominate the government and security forces and are the bedrock of the Hashemite monarchy.
Traditionally, many of the IAF's supporters have been Jordanians of Palestinian origin.
The opposition also demanded that parliament, rather than the king, should have the right to appoint and dismiss the prime minister.
Despite the call for reforms, Jordan has so far avoided the unrest and political upheaval that rocked much of the Arab world last year. Protests have been relatively small and have not gained the same level of political momentum as those in Tunisia, Egypt, Libya, Yemen and Syria.
Correction 25 January 2013: A previous version of this story incorrectly stated that members of the Jordanian security forces were allowed to vote for the first time.


Facebook users solved the mystery of a lost memory card in under an hour after an appeal was posted by a police force.

Essex Police asked for help in reuniting the card, containing wedding pictures and of a family holiday, with its owners after it was handed in at Clacton police station on Friday.
The post was shared almost 700 times and owner Chelsey Elliott was found 45 minutes later.
A number of users questioned Essex Police's detective work over the post.
"It should not be that hard to find the owners," wrote one Facebook user.
"A quick Google finds out who arranged the marriage in Kenya for them. Pretty sure you can ask them for contact details."
Within 10 minutes, friends and relatives of Rikki and Chelsey Elliott had realised the connection and "tagged" the rightful owners.
Some people praised the force's use of social networking in cracking the case.
"The power of Facebook being used in a good way for once. Well done all," said one man.
Mrs Elliott said she was a "very happy lady" and thanked everyone who had contacted her following the appeal.
"Many, many kind people out there. Thank you everyone," she wrote.


Loughborough Lightning secured a 43-run, bonus-point win over Yorkshire Diamonds in the first match of the inaugural Super League at Headingley.

The match attracted nearly 1,000 fans and was lit up by Loughborough spinner Rebecca Grundy's 3-21.
New Zealander Sophie Devine's excellent 52 helped the visitors to post 128-9.
In reply, the Diamonds never recovered from having home captain Lauren Winfield controversially run out for 23 and they were bowled out for 85.
Lightning's decision to bat in the first ever professional women's domestic cricket match looked suspect when captain Georgia Elwiss was stumped off Danielle Hazell for 10, having danced down the track to the spinner.
The visitors recovered well through Devine and Ellyse Perry, with the former clubbing 14 off Katie Levick's first over, including a huge six that sailed almost 15 metres over the long-off boundary.
However, Loughborough's innings hinged on Perry's run out by wicketkeeper Beth Mooney, as the Australian all-rounder's side slipped from 85-2 to 97-7, including Devine being brilliantly caught in the deep by Jenny Gunn off Levick.
A few lusty blows from Paige Scholfield and Eve Jones, though, restored some forward momentum in the final overs.
The Diamonds never looked like getting close to their target after England opener Winfield walked back to the dugout in disgust - having felt she was obstructed by Perry.
Spinner Grundy and medium-pacer Elwiss took 5-27 between them in seven overs as they strangled their opposition, dismissing Yorkshire with 17 balls remaining.
Loughborough Lightning all-rounder Sophie Devine: "It was nice to get some runs on the board, I felt we were 15-20 runs short and it didn't help when I ran out Ellyse Perry.
"We bowled fantastically well as Yorkshire came out really hard at us, which we knew they would, so it was a great team effort.
"With the sizes the boundaries are, we know how important fielding is going to be. Every run counts, and we have had a real focus on diving.
"It is a real honour to be here, be playing in this competition and with and against so many great players."
Media playback is not supported on this device


An American farmer has been sharing his passion for Scotland's Highland cattle on social media.

With his wife Kathryn, Marc Stewart looks after two Highlanders at their farm in the foothills of Virginia's Blue Ridge Mountains.
Videos and photographs of the cattle, called Hamish and Kyloe, posted to social media by Mr Stewart have been viewed thousands of times.
Some of the most popular posts feature red-haired Hamish relaxed as his shaggy coat is combed.
Mr Stewart's interest in the breed began with a fascination in Scotland in general after making a trip there 15 years ago.
His first "Highland" was Hamish, who he bought when the beast was 10 months old. Hamish turns six later this year.
"My love of Scotland was first," says Mr Stewart.
"After that, the Highland was just an extension of Scotland. To me, loving Scotland meant loving Highlands - and their massive horns and shaggy fur always made me think of woolly mammoths.
"Who wouldn't want a woolly mammoth for a pet?"
Asked to describe his Highlanders' personalities, Mr Stewart says: "That's an easy one.
"Hamish is easy going, laid back and usually very calm and collected. He's happy standing in the pond or laying in the shade under an old oak.
"Kyloe, is the consummate "little brother". Always getting into things he shouldn't, testing fences, beating up gate panels or loose buckets and his favourite, trying to get Hamish stirred up enough to push back."
Hamish and Kyloe are members of one of Britain's oldest and hardiest breeds of cattle.
According to the Highland Cattle Society, whose patron is the Queen, written records of the distinctive-looking beasts go back to the 18th Century.
The Highland Cattle Herd Book, which lists pedigrees, was first published in 1885.
Herds of Highlanders, also affectionately known as Heilan Coos, are known as folds and these have been founded across the world.
Kyloe is another name for black haired West Highland Cattle.
Hundreds of thousands of these cattle used to be raised in the Highlands and Islands.
Mr Stewart believes the pair, along with a pig called Siggy, have become popular online because of their appearance.
He says: "People see this massive horned animal being loving and gentle and they're used to seeing that behaviour from a dog or something.
"But having a 2,000lb animal act that way is something entirely different.
"The size is a bit intimidating for most. They see a puny human controlling this great shaggy beast and are amazed at his obvious raw power and strength.
"I would also like to add that they are very intelligent.
"Hamish goes to great lengths to avoid hitting me with his horns, unless he's bumping my arm in an effort to get me to brush him more."
Mr Stewart adds: "I am in the process of publishing my first book ever, not bad for a guy who dropped out of high school because of dyslexia which was not understood as it is now, on my adventures in Scotland.
"My first trip 15 years ago, is what led me to decide to get Highlands."


Prime Minister Theresa May is unlikely to address the Dáil (Irish parliament) on her visit to the Republic of Ireland later this month.

Taoiseach (Irish prime minister) Enda Kenny had invited Mrs May to give a speech to TDs (MPs).
"My understanding is that the Prime Minister's schedule will not allow that to happen and I am not in control of that schedule," Mr Kenny told the Dáil.
Mrs May and Mr Kenny are expected to discuss Brexit during the Dublin visit.
Mrs May would have been only the second UK prime minister to speak before the Dáil.
Tony Blair addressed the Dail in 1998, the first speech to the parliament by a UK prime minister since 1922.


Leinster have confirmed that Ian Madigan will leave the Irish province at the end of the season to join French Top 14 side Bordeaux Begles.

Fly-half Madigan, capped 25 times by Ireland, said he believed the "timing was right" to make the move to France.
"This was a very difficult decision for me to make, leaving the club that I have represented my whole professional life," said the 26-year-old.
"I look forward to experiencing a new life and style of rugby in France."
Madigan has played 135 times for Leinster to date, amassing 765 points and scoring 24 tries since making his debut in May 2009.
He has won two Heineken Cups, a Challenge Cup and two Pro12 titles during his time with the province, and has also been part of Ireland's Six Nations-winning squads in 2014 and 2015.
He has however found himself behind Johnny Sexton in the pecking order at Leinster and Ireland for much of his career, a role he has occupied again since Sexton's return from Racing Metro in the summer.
The player was also understood to be a a target for Bristol and Harlequins, but opted to make the move to France despite a warning from Irish Rugby Football Union high performance director David Nucifora that "players that go [abroad], leave themselves at a disadvantage".
Madigan excelled in Ireland's 24-9 victory over France that set up a Rugby World Cup quarter-final against Argentina, stepping in for Sexton at short notice.
The fly-half was unable to repeat that performance against the Pumas however, as Ireland slipped to their sixth World Cup quarter-final defeat.
Bordeaux are currently fifth in the Top 14 and bottom of Pool 2 in the Champions Cup, behind Exeter Chiefs, Clermont and Ospreys.
"It is a challenge I'm looking forward to. Bordeaux are a team that is making strides in the Top 14 and in Europe and I look forward to being part of that journey," said Madigan, who can also play at centre.
"There is a huge few weeks and months ahead with Leinster, and I look forward to playing my part and trying to finish the season out as strongly as possible for them."
Leinster head coach Leo Cullen described Madigan as "a tremendous servant to Leinster and Irish rugby".
"We fully understand his motivations for deciding to join Bordeaux and wish him well for the future," said Cullen.


Head coach Bobby Crutchley has named six Olympians in his England squad for the four-Test series in South Africa in March.

England play the hosts and Germany twice each, in preparation for June's World League Semi-Final in London.
Rio Olympian Sam Ward could win his 50th international cap and Chris Griffiths returns from injury.
The 21-strong group also includes nine uncapped players, with places for U21s stars Jack Turner and Peter Scott.
Captain Barry Middleton, Adam Dixon and Mark Gleghorne will be rested after competing in the Hockey India League while Harry Martin is unavailable because of club commitments with Rotterdam.
Crutchley said: "The trip is a great opportunity to expose the new squad to international matches early in the cycle.
"With matches against Germany and South Africa it provides an ideal opportunity to start our preparations for the World League Semi-Final and Europeans later in the year."
Full squad: James Albery, Ollie Willars (Beeston), David Ames, George Pinner, Sam Ward (Holcombe), Liam Ansell, Brendan Creed, Harry Gibson, David Goodfield, (Surbiton), Tom Carson (Reading), Chris Griffiths (East Grinstead), Jonty Griffiths, Ed Horler, Luke Taylor (Loughborough Students), Mikey Hoare, Phil Roper, Ian Sloan, Henry Weir (Wimbledon), Liam Sanford (Team Bath Buccaneers and RAF), Peter Scott (Team Bath Buccaneers), Jack Turner (University of Durham).


A police officer has received a suspended 12-week sentence after pleading guilty to four charges of making indecent images of children.

Stephen McMillan, 26, admitted making and distributing the images.
The Metropolitan Police officer, of Viridian Square, Aylesbury, filmed a teenage girl performing a sex act on him and sent it to three friends.
He was sentenced at High Wycombe Magistrates' Court and placed on the Sex Offenders Register for five years.


Government policies are placing a "cumulative burden" on businesses, the Confederation of British Industry (CBI) has warned.

It said policies including the National Living Wage, the apprenticeship levy and pension auto-enrolment. had placed "a number of strains" on businesses.
It warned such strains were "adding up" and could put UK economic growth and job losses at risk.
The CBI also attacked the government's "wrong-headed" visa policies.
Business have repeatedly warned that the National Living Wage, which the government says will rise to Â£9 per hour by 2020, will place a significant burden on small businesses, in particular in the hospitality sector.
They have also raised concerns about the government's proposals to increase the number of apprenticeships to three million but expect industry to bear much of the cost of providing training.
Meanwhile, pensions auto-enrolment is still being rolled out with some small businesses still not expected to provide work place pensions until 2018.
"Overall, UK policymakers need to deliver regulatory stability and predictability. Businesses struggle to invest when the rules repeatedly change - as we have seen in the energy sector where policy shifts have chilled investment," CBI director general Carolyn Fairbairn said highlighting the recent withdrawal of subsidies for green energy schemes.
While she acknowledged public concerns about immigration and pressures on some public services, Ms Fairbarn called on the government to "reform the UK's wrong-headed visa policies that are keeping global talent from our growing firms and global student from our world class universities".
Ms Fairbarn added that while the economy had recovered strongly from the financial crisis it could be "all too easily undermined by the short-termism of modern politics. We need to avoid this pattern in 2016, and keep a sharp eye on the long-term".
The CBI director-general also called the delay in the government's decision over airport expansion in southern England an "abject failure of leadership".
She said the government must "take the big decisions on infrastructure, especially in aviation and energy, and get building roads, rail and more homes".
"Good business needs good infrastructure - yet the UK currently ranks 24th in the world, according to the World Economic Forum. We have fallen badly behind over many decades - we must catch up and then pull away,"  she added.


The quest to find King Arthur's Camelot has puzzled and intrigued scholars and fans for over a thousand years.

The mythical ruler's legendary court has been associated with locations throughout Wales, including Carmarthen, St David's, and Cardigan.
Now a retired Bangor University professor has revealed what he believes to be the true location of Camelot.
And it turns out to be a small Roman fort at Slack, on the outskirts of Huddersfield in West Yorkshire.
Prof Peter Field, a renowned expert in Arthurian literature, said:  "It was quite by chance. I was looking at some maps, and suddenly all the ducks lined up.
"I believe I may have solved a 1,400-year-old mystery."
Previous best guesses for the location of the round table include Caerleon in Newport, Somerset's Cadbury Castle, and Tintagel in Cornwall.
In Roman times, Slack was home to a fort called Camulodunum, which means "the fort of the god Camul".
Over the years, well-recognised linguistic processes would have reduced Camulodunum to Camelot.
Though almost forgotten and insignificant today, and even though it was abandoned and dilapidated by the relevant time of King Arthur around A.D. 500, Prof Field argues that this site at Slack would still have been considered a strategic stronghold.
At that time, Celtic-speaking Britons, who could have been led by King Arthur, held the north and the west coast against the invading Anglo-Saxons.
Slack, on the Roman road from Chester to York, would have been the ideal location from which to defend the east coast.
Prof Field added: "If there was a real King Arthur, he will have lived around AD500, although the first mention of him in Camelot is in a French poem from the Champagne region of France from 1180.
"There is no mention of Camelot in the period between those dates, known as the Dark Ages, when the country was at war, and very little was recorded.
"In this gap, people passed on information, much got lost in transmission, and people may have made up facts or just messed up known information."
Prof Field, who taught at Bangor from 1964 to 2004, has been researching the location of Camelot for the past 18 months.
He spoke about his findings during the official launch of Bangor University's Stephen Colclough centre for the history and culture of the book.


Yorkshire have completed the signing of Australia batsman Shaun Marsh as an overseas player for the T20 Blast.

Marsh, 33, will arrive in the UK on Sunday and could make his debut against Nottinghamshire on 7 July.
The county moved to sign Marsh after Travis Head was called into the Australia A squad.
"I've only heard positive things about from previous overseas players and can't wait to be involved," said Marsh.
Meanwhile, the club have confirmed captain Gary Ballance will be available for the first two days of the County Championship day-night match against Surrey, starting on Monday, 26 June.
Ballance, who has scored 815 runs at an average of 101.87 in the County Championship this season, has been called into the England Lions team for the game against South Africa which starts on Thursday, 29 June.


A three-year deal has been struck with Natural Resources Wales over the use of forests for Wales Rally GB events.

The Motor Sports Association (MSA) agreed deals in England and Scotland, but talks had stalled with NRW.
The body had said it needed to ensure organisers covered the cost of repairing forestry roads afterwards.
There were fears rallying may have to stop in Wales if a deal could not be reached.
Talks are continuing over stage rally mileage charges with other parties.
Wales hosts several competitions with Wales Rally GB including the final round of the FIA World Rally Championship (WRC), the most high profile with stages in Powys, Gwynedd and Denbighshire last year.
A national rally stage in Wales costs about Â£500 to enter, with organisers needing about 80 competitors to break even.
Popular forest roads in Hafren, Myherin, Clocaenog and Dyfi are all looked after by NRW and will feature in the UK round of the FIA World Rally Championship next month.
Tim Jones of NRW said: "The forest roads we look after have achieved almost legendary status in the world of rallying."
He said he hoped the new access agreement would send a positive message to the rallying community.
Rob Jones, MSA Chief Executive, said: "[The agreement] forms the essential platform for us to continue to focus on mileage charges and the wider partnership between our two organisations."


Police are considering claims that the Conservatives broke the law by using a Neath call centre to canvass voters, an MP has said.

An investigation by Channel 4 claimed the UK Tories contracted Blue Telecoms to conduct marketing campaigns ahead of the general election.
A Conservative spokesman had said all the calls were compliant with the law.
Labour MP Wayne David said South Wales Police were looking into the claims.
Speaking in the Commons on Thursday, Mr David said the Electoral Commission had written to him confirming the police were "formally considering the allegations".
An undercover investigation by C4 News, broadcast last month, claimed call centre workers may have been carrying out paid canvassing, banned under electoral law, as they promoted key Conservative messages to undecided voters in the weeks before the election.
The investigation claimed that calls were made to voters in key marginal seats, including Bridgend, Gower, Clwyd South and Wrexham.
At the start of the election campaign, the information commissioner, Elizabeth Denham, contacted all parties to remind them of the law around direct marketing.
At the time a Conservative spokesman said: "All the scripts supplied by the party for these calls are compliant with data protection and information law".
Caerphilly MP Mr David told BBC Wales that he would be speaking with South Wales Police in the next few days to establish the nature and scope of the inquiry.


Barcelona's ability to offer Lionel Messi an improved contract will rest on their capacity to raise revenue from sponsorship deals and player sales, chief executive Oscar Grau says.

Messi's contract expires in 2018 and he is expected to command a new deal on a par with the reported £21m a year earned by Luis Suarez and Neymar.
But La Liga's salary cap means Barca must exercise common sense, Grau said.
"We want the best players but perhaps we have to prioritise," he added.
La Liga agrees budgetary limits with each club at the start of every season, which prevents boards from spending more than 70% of their budget on wages.
The big-money contracts awarded to Messi's fellow forwards Suarez and Neymar, which run until 2021, eat into a significant part of their wage budget, which must also absorb an average player salary of £5.6m - the highest in La Liga.
Messi, 29, reportedly earns about £19m and Grau admitted any increase had to be considered with a "cool head".
"We have to make the numbers add up," he added. "One option is to increase our revenues, as our economic strategy forecasts.
"The club wants the best player in the world to stay at Barca. I would like to ease the concerns of club members and supporters but we have to use common sense."


Auditors have said the European Union has failed to keep tight enough control over its own spending.

The European Court of Auditors said there were errors in allocating about 5bn euros (Â£4bn) from the 2011 budget.
Critics said it showed the EU's wastefulness, at a time when it was arguing for a budget increase.
Court President Vitor Caldeira said: "With Europe's public finances under severe pressure, there remains scope to spend EU money more efficiently."
He added: "Member states must agree on better rules for how EU money is spent, and member states and the commission must enforce them properly."
The court's report said most errors arose from "misapplication or misunderstanding" of the EU's complex rules, though there were some suspected cases of fraud.
It also said the failures were often down to the national and local governments responsible for overseeing the distribution of funds, rather than just the European Commission.
"A little more effort by member states to control projects properly and retrieve misused funds could go a long way, particularly in this time of economic difficulty," said the EU's Audit Commissioner Algirdas Semeta.
However, critics said the commission itself must also accept some of the blame.
"The European Commission is ultimately responsible for all EU monies spent and it falls to them to take responsibility for this report," said Martin Callanan MEP, of Britain's Conservative Party.
EU budget plans in detail
"It is risible that the commission wants a 5% increase in the EU budget, yet nearly 4% of spending is affected by error. Before asking for more taxpayers' money, perhaps the commission should prioritise better spending of the money it already has."
National leaders will meet for a summit in two weeks' time to try to hammer out the next seven-year budget.
Britain has been leading demands for a freeze, saying proposals for an increase are incompatible with a time of austerity.
A number of countries which are net contributors to the budget are also arguing for restraint.
But net-recipient countries argue that the EU's spending on agriculture and regional development are valuable ways of stimulating the economy.


Cyber-thieves have made at least $25m (£19m) from ransomware in the last two years, suggests research by Google.

The search giant created thousands of virtual victims of ransomware to expose the payment ecosystem surrounding the malware type.
Most of the money was made in 2016 as gangs realised how lucrative it was, revealed a talk at Black Hat.
Two types of ransomware made most of the money, it said, but other variants are starting to emerge.
"It's become a very, very profitable market and is here to stay," said Elie Bursztein from Google who, along with colleagues Kylie McRoberts and Luca Invernizzi, carried out the research.
Ransomware is malicious software that infects a machine and then encrypts or scrambles files so they can no longer be used or read. The files are only decrypted when a victim pays a ransom. Payments typically have to be made using the Bitcoin virtual currency.
Mr Bursztein said Google used several different methods to work out how much cash was flowing towards ransomware creators.
As well as drawing on reports from people who had paid a ransom, it sought out the files used to infect machines and then ran those on lots of virtual machines to generate "synthetic victims", he said.
Cyber-hacks season:
It then monitored the network traffic generated by these victims to work out to where money would be transferred. The data gathered in this stage was also used to find more variants of ransomware and the 300,000 files it found broke down into 34 of them, he said.
The most popular strains were the Locky and Cerber families, added Mr Bursztein.
Payment analysis of the Bitcoin blockchain, which logs all transactions made using the e-currency, revealed that those two strains also made the most money over the last year, he said, with Locky collecting about $7.8m (£5.9m) and Cerber $6.9m (£5.2m).
The research project also revealed where the cash flowed and accumulated in the Bitcoin network and where it was converted back into cash. More than 95% of Bitcoin payments for ransomware  were cashed out via Russia's BTC-e exchange, found Google.
On 26 July, one of the founders of BTC-e, Alexander Vinnik, was arrested by Greek police on money laundering charges. The police were acting on a US warrant and his extradition to America is being sought.
The gangs behind the ransomware explosion were not likely to stop soon, said Mr Bursztein, although established strains are facing competition from newer ones.
"Ransomware is a fast-moving market," he said. "There's aggressive competition coming from variants such as SamSam and Spora."
Novel variants were expanding quickly and many were encouraging fast expansion by paying affiliates more if they placed the malware on to large numbers of machines. The ransomware as a service model was already proving popular, he warned.
"It's no longer a game reserved for tech-savvy criminals," he said. "It's for almost anyone."
This week BBC News is taking a close look at all aspects of cyber-security. The coverage is timed to coincide with the two biggest shows in the security calendar - Black Hat and Def Con.
Follow all our coverage via this link


Work has started to rebuild a Viking museum which was forced to close because of severe flooding.

Jorvik Viking Centre, in York, closed on 27 December, after parts of the attraction were submerged beneath up to 3ft (1m) of water from the flooded River Foss.
A campaign to raise £1.5m towards the cost of rebuilding the museum has so far raised about £500,000.
The centre is expected to reopen in Spring 2017.
The museum, which is owned by the York Archaeological Trust, opened in 1984.
The city's Norse history was revealed in the 1970s when an archaeological dig at Coppergate found Viking streets buried below the modern pavement.


Prime Minister Theresa May has said more must be done to tackle terror online.

In a speech on Sunday, following the terrorist attack in London, she said the internet provided a "safe space" for extremist ideology to breed.
But technology companies and cyber-security experts have warned that tighter regulation of the internet will not solve this problem.
Messages sent online can be scrambled as they leave one device and they remain scrambled until they are deciphered by the recipient's device.
This is end-to-end encryption, and it stops messages being read by third parties - be it criminals or law enforcement - if they are intercepted.
This adds valuable security to the messages we send online, which could contain private information, bank details and personal photographs.
Some apps such as WhatsApp already add end-to-end encryption to messages automatically.
However, this does mean that theoretically messages can be sent that police or other authorities cannot read if they intercept them.
On Sunday, Mrs May said there should be no messages that law enforcement "cannot read", while Home Secretary Amber Rudd said she wanted tech companies to "limit the use of end-to-end encryption".
Critics say disabling encryption in popular apps will not deter criminals - they could simply switch from one app to another, or create their own messaging apps.
Meanwhile, messages sent by law-abiding citizens would become "easy for criminals, voyeurs and foreign spies to intercept", journalist and former digital rights activist Cory Doctorow wrote in a blog.
Cyber-security experts are particularly critical of the notion that messaging apps should have a "back door" in their systems, to let authorities read users' messages.
"It's impossible to overstate how bonkers the idea of sabotaging cryptography is to people who understand information security," said Mr Doctorow.
"Use deliberately compromised cryptography, that has a back door that only the 'good guys' are supposed to have the keys to, and you have effectively no security."
Even if app-makers were ordered to stop using encryption, it would be very difficult to stop criminals encrypting their messages manually, or writing them in code.
On Sunday, Mrs May said large internet companies provided a "safe space" for extremist ideology to breed.
Earlier this year, a Home Affairs Select Committee report said social networks were "shamefully far" from tackling illegal and dangerous content and took too long to remove offending posts.
The volume of material uploaded to Facebook, Twitter, YouTube and other social networks is astonishing, making it difficult to moderate.
YouTube says 400 hours worth of video are uploaded to its platform every minute, making it impossible to review every clip a user posts.
The Open Rights Group, which campaigns for online freedoms, said governments and companies should "take sensible measures to stop abuse" but warned that "attempts to control the internet" would be difficult to enforce.
Technology companies have defended their handling of extremist content following the London terror attack.
YouTube told the BBC that it received 200,000 reports of inappropriate content a day, but managed to review 98% of them within 24 hours.
It said hate speech made up a small proportion of the "tens of millions" of videos it removed every year.
Facebook said: "Using a combination of technology and human review, we work aggressively to remove terrorist content from our platform as soon as we become aware of it - and if we become aware of an emergency involving imminent harm to someone's safety, we notify law enforcement."
It said it actively worked to identify extremist accounts and worked with rivals Microsoft, Twitter and YouTube to help identify such content.
Both Facebook and Google have stated that extremist content has no place on their websites.
Germany has tried to further motivate internet giants, by threatening them with fines of up to 50m euros (Â£43.5m) if they fail to remove hate speech quickly.
However, the Open Rights Group warned that tough regulation by governments "could push these vile networks into even darker corners of the web, where they will be even harder to observe".


A 21-year-old trekker from Taiwan has been rescued alive in the Himalayas, 47 days after he and his girlfriend went missing.

A high-altitude search and rescue team found Liang Sheng Yueh in a canyon at around 2,600m (8,500ft) near Tipling village in Nepal's Dhading district.
The body of his companion, 19-year-old Liu Chen Chun, was lying nearby.
Mr Liang is being treated at Grandee International Hospital in Kathmandu and is said to be out of danger.
Dr Sanjaya Karki, who is treating Mr Liang, told Surendra Phuyal of BBC Nepal: "He can speak slowly. He told me his girlfriend died three days ago. He doesn't have trauma injuries, but his body has injuries stemming from worm-bites."
The trekker is said to have lost 30kg (4.5 stone) since going missing seven weeks ago. His hair was full of lice when he was found, and one foot was covered with maggots.
Doctors said he appeared to have survived largely on water and salt.
The BBC has learned that the stricken travellers were first sighted at 11:00 local time (05:15 GMT) by local people. A helicopter was immediately sent to the scene.
Mr Liang and Ms Liu, first year students at Taiwan's National Dong Hwa University, had arrived in Nepal in February from India.
They were last seen in northern Dhading on 9 March, where they had gone out trekking despite heavy snowfall.
The website Missingtrekker.com reported that the couple had experienced some hardships before their trek, including missing luggage, and argued over "trivial matters".
Ms Liu reportedly wrote on Facebook: "I wish I had never ended up here."
The pair's families became concerned when they failed to call Taiwan as arranged on 10 March, and requested official help to find them five days later.
Nepalese police hired three guides and a helicopter to search for the students, who were believed to be travelling to meet Taiwanese friends in Langtang village.
According to the Taipei Times, Himalayan travel guides and local news outlets were also alerted to the situation, but ongoing snowfall and sporadic avalanches made an extensive search difficult.
Madhav Basnet, who was part of the rescue operation, told the BBC the two trekkers appeared to have "slid off a slippery trail while making an ascent towards Ghatlang village from Dhading".
"It looks like they fell off and got trapped in a cave-like formation and couldn't climb back up again," he added.


Princess Charlotte has been sent gifts from 64 countries across the world to celebrate her first birthday.

The presents were received from world leaders, community groups and well-wishers. Prime Minister David Cameron gave her a copy of Hans Christian Andersen's Fairy Tales.
The gift list, released by Kensington Palace, also included toys and clothes.
A spokeswoman for Kensington Palace said the Duke and Duchess of Cambridge were "incredibly grateful".
"The couple have taken a number of gifts into their home, some gifts are stored within the Royal Household, and some gifts were donated to organisations which could make good use of them," the spokeswoman added.
Some of the letters, gifts and good wishes were received in the year since Princess Charlotte was born.
Four photos of the princess, taken at home by her mother, the Duchess of Cambridge, were released on Sunday.
The gifts include a New Zealand Rugby sleepsuit and Wellington Rugby snowsuit, brought back by her uncle Prince Harry during his recent tour of New Zealand.
That country's prime minster, John Key, gave a selection of teddy bears, baby blankets and bootees, all made from Stansborough wool.
The Australian government sent a cot blanket made from Tasmanian merino wool, sourced from Launceston's renowned Waverley Woollen Mills.
The blanket is embroidered with the Australian floral emblem, the wattle, by members of the ACT Embroiderers' Guild, which also donated 10,000 Australian dollars (Â£5,200) to the Healesville Sanctuary, a bushland haven for wildlife.
Prime Minister of Canada Justin Trudeau gave a snowsuit, a book, and donated 100,000 Canadian dollars (Â£54,500) to Immunize Canada, which promotes the use of vaccines.
During last year's Chinese state visit by President Xi Jinping, Princess Charlotte was given a set of silk figurines, depicting the traditional Chinese story, Dream of the Red Chamber.
And during their recent visit to the UK, the president and the first lady of the United States, Barack and Michelle Obama, gave the princess a jigsaw and a "Bo" soft toy - of their Portuguese water dog - to match one owned by Prince George.
And when the duke and duchess visited Bhutan last month, they were given coats by the nation's king and queen for both Prince George and Princess Charlotte.


The Football Pools could be about to change hands after Netplay TV said it was in talks to buy the business from current owner Sportech.

Reports say the business, which began 92 years ago and was once a major focus for betting, may fetch up to £100m.
Sportech combined the pools brands by buying Littlewoods Gaming in 2000, Zetters in 2002 and Vernons in 2007.
The pools are now played by about 300,000 people, though at their height 10 million players took part.
Players pick up to 12 games that they predict will finish in a draw, with each team scoring at least two goals.
Famous winners include West Yorkshire factory worker Viv Nicholson who scooped £152,319 in 1961, the equivalent of £3.1m today, and vowed to "spend, spend, spend" her winnings.
Trading in Netplay shares on Aim, the stock exchange index for smaller, fast-growing companies, was suspended after it confirmed it was in talks with Sportech.