The first details of how a drug could slow the pace of brain decline for patients with early stage Alzheimer's disease have emerged.

Data from pharmaceutical company Eli Lilly suggests its solanezumab drug can cut the rate of the dementia's progression by about a third.
The results, presented to a US conference, are being met with cautious optimism.
A new trial is due to report next year and should provide definitive evidence.
The death of brain cells in Alzheimer's is currently unstoppable. Solanezumab may be able to keep them alive.
Current medication, such as Aricept, can manage only the symptoms of dementia by helping the dying brain cells function.
But solanezumab attacks the deformed proteins, called amyloid, that build up in the brain during Alzheimer's.
It is thought the formation of sticky plaques of amyloid between nerve cells leads to damage and eventually brain cell death.
Solanezumab has long been the great hope of dementia research, yet an 18-month trial of the drug seemingly ended in failure in 2012.
But when Eli Lilly looked more closely at the data, there were hints it could be working for patients in the earliest stages of the disease.
It appeared to slow progression by around 34% during the study.
So the company asked just over 1,000 of the patients in the original trial with mild Alzheimer's to take the drug for another two years.
And positive results from this extension of the original trial have now been presented at the Alzheimer's Association International Conference.
They show those taking the drugs the longest had the most benefit.
Dr Eric Siemers, from the Lilly Research Laboratories, in Indiana, told the BBC: "It's another piece of evidence that solanezumab does have an effect on the underlying disease pathology.
"We think there is a chance that solanezumab will be the first disease-modifying medication to be available."
The company also started a completely separate trial in mild patients in 2012, and these results could prove to be the definitive moment for the drug.
Analysis
Today is not the day to jump up and down proclaiming a breakthrough in slowing the pace of Alzheimer's.
The limited data which has been released is the scientific equivalent of a poll before a general election or a trailer ahead of a movie.
It provides captivating clues, hints and teases, but nothing definitive.
At the moment there is no medication that can slow down dementia. If such a drug was developed it could transform how the disease is managed.
People would still get worse, but they would spend more time in the milder phase of the degenerative disease rather than needing constant care.
In a field that has been plagued by repeated disappointment, even a hint of such a drug is an exciting moment.
Next year, when further trial results are due, we will know for certain whether solanezumab is the breakthrough everyone hopes it could be.
Dr Eric Karran, the director of research at Alzheimer's Research UK, told the BBC News website: "If this gets replicated, then I think this is a real breakthrough in Alzheimer's research.
"Then, for the first time, the medical community can say we can slow Alzheimer's, which is an incredible step forward.
"These data need replicating, this is not proof, but what you can say is it is entirely consistent with a disease-modifying effect.
"We've never ever had evidence that we can affect the disease process."
Clare Walton, the research manager at the Alzheimer's Society, told the BBC: "The data hints that the antibodies are having an effect, it is promising and it's better than no effect, but it's inconclusive.
"After a decade of no treatments and many drug failures, it's exciting to get promising news, but it doesn't really tell us either way, and we need to wait for the phase-three study, and that is in 18 months."
In the first stage of the original trial, which ended in failure, half of the patients with Alzheimer's were given solanezumab and half were not.
A reanalysis of the cognition scores of the patients with mild Alzheimer's suggested taking the drug had cut the rate of the disease's progression by about 34%.
The implication is that the amount of cognitive decline normally seen in 18 months would take 24 months with the drug.
In the extension of the original trial, all of the 1,000-plus mild Alzheimer's patients participating were given solanezumab.
So, at the end of the extension, half of them had been taking the drug for three and a half years while the other half had been taking it for two years.
The latest data shows those taking solanezumab for the longest time still had better scores of cognitive function.
This suggests the course of the disease was being slowed.
If the patients' brains had continued to decline at the normal pace and the drug had been merely helping with symptoms, then all of the patients participating in the extension of the original trial - whether they had been taking solanezumab for three and a half or two years - would have had similar scores of cognitive function.


A bid to stop proposed changes to sixth form education in Pembrokeshire has failed.

The council is to reorganise secondary schools to improve standards, deal with ageing school buildings and increase Welsh language provision.
Opposition councillors lost a vote to stop the plans at an extraordinary meeting on Tuesday by 22 votes to 29.
Earlier, about 150 protesters gathered outside the council's Haverfordwest office.
Parents and students from action group Save our Sixth Form fear a lack of continuity could be harmful to the prospects of some pupils.
Kay Dearing, a parent governor at Tasker Milward School, told BBC Radio Wales: "I feel very strongly that no-one has yet demonstrated that the proposed model is to the benefit of the pupils."
Changes include closing three sixth forms with pupils attending a new centre in Haverfordwest, along with merging two schools and building a new Welsh medium secondary school.
A consultation on the proposals ends on 5 May.


Ex-F1 boss Bernie Ecclestone says the sport's owners do not want him involved in the running of the business.

The 86-year-old, ousted when US group Liberty Media took over F1 in January, said the new owners "believe I haven't done a very good job".
"The last thing they need is me to have any input because they want to change things," Ecclestone told BBC Sport.
I've been upgraded from chief executive to a much higher position. It's so high, I can't even see what's going on
"They know I would have changed them before if I thought they needed changing."
Ecclestone, who is attending a race for the first time this season in Bahrain this weekend, has been kept on by the F1 Group in a new role as chairman emeritus, in which he can be consulted for advice.
Asked if he was missing his former role, Ecclestone said: "Not particularly, I'm still in F1.
"What people don't understand is I'm still in the company. Everything's the same.
"I've been upgraded from chief executive to a much higher position. It's so high, I can't even see what's going on."
He added: "It's not a case of things being difficult or not being difficult. You've got what you've got and you've got to do [what you can] with what you've got.
"Imagine if suddenly a doctor said you've got cancer. Nothing I can do about it. You've got to get on with life as it is. Which is what I'm doing."
New F1 chairman Chase Carey has paid tribute to the work Ecclestone has done in establishing F1 as a major global sport, but said he felt it was time for a new approach.
"I think over Bernie's career he deserves a great deal of credit for the sport that was built," said Carey.
"In recent years there are things we think can be done to really take the sport to another level so we are looking to bring in a number of new initiatives, marketing, digital, sponsors, and create more of a spirit of partnerships amongst the teams, the promoters and the like."
Asked if he believed the new owners would continue to be able to bring in $1.5bn a year in revenue, Ecclestone said: "No idea. [They] should do better.
"That's the reason they bought it because they thought I hadn't done a very good job and they could do better and they probably will."
Under Carey, F1 is now run on a day-to-day basis by former Mercedes team boss Ross Brawn and US television marketing expert Sean Bratches.
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Asked whether he had faith in them, Ecclestone: They have bought the car and they are going to drive it. It is not a case of having faith.
"They have bought a company and they are going to make it work."
The new owners want to open up the sport and expand its audience, partly by exploiting digital media. They have already loosened restrictions on what teams and drivers can show from inside the track on social networks.
Ecclestone, who has long said he does not see the internet as a valuable tool, said: "We probably mucked around with that before even people called it social media. While it was on my watch we were exploring social media.
"That's why I didn't explore it too much because I couldn't see too much coming out of it. It was just going to be enormous cost."
Liberty, now renamed the F1 Group, is for now operating within the contracts Ecclestone completed before his departure.
One of the most controversial was his decision to sell the UK TV rights exclusively to pay-television channel Sky from 2019-24. The deal is said to be worth in the region of £160m a year but some teams are concerned about what they see as an inevitable drop in audiences.
Asked whether going behind a paywall was the right approach, Ecclestone said: "I wouldn't have done it, but I don't know. These people are TV specialists."
When it was pointed out that he did the deal, he said: "No, the Sky deal I was happy with, they do a bloody good job. I would have rather stayed with the BBC but they couldn't afford to keep F1; that's why we lost them.
"The BBC did a super job and I was disappointed we lost them but I was happy Sky have come up and done a good job."
He added that coverage on free-to-air television was "important for everybody".
"It's important you can capture people that by accident are watching and then stay when they see what they like, which is what happened with the BBC."
Sky has said the British Grand Prix and highlights of other races will be shown on free to air from 2019, but is not yet clear on whether that is on one of its own channels or if the rights will be sold on to one of the major terrestrial channels.


A new conservation area has been set up in waters off the west of Scotland to help protect harbour porpoise.

A so-called Special Area of Conservation (SAC) has been created in the Inner Hebrides and Minches.
The facility is the largest conservation area for the marine species in Europe.
Scientists warned earlier this year that numbers of harbour porpoise were falling because of difficulties with catching food and breeding.
They had called on the Scottish government to act and introduce protected sites for the animals.
Environment Secretary Roseanna Cunningham said she was pleased to designate the first SAC and added: "This will help maintain the favourable conservation status and provide protection to the species and their habitats."
WWF Scotland director Lang Banks welcomed the move and said he was hopeful more such sites would be established in future.
He said: "It's fantastic news that Europe's largest Special Area of Conservation for harbour porpoise is to be located off the west coast of Scotland.
"We've long called for greater protection for this species and we look forward to working with the Scottish government and others to ensure that this site contributes to a coherent and well-managed network of marine protected areas."


Ospreys will be without Wales flanker Justin Tipuric when Scarlets visit them in the Pro12 on Saturday.

Tipuric was injured in Wales' Six Nations win over Italy and is undergoing tests for concussion.
Ospreys have also confirmed the Scarlets game will be the first lock Alun Wyn Jones misses as he tries to overcome a heel injury.
Gloucester's Ross Moriarty scored two tries as Tipuric's replacement in Wales' rout of the Azzurri.
Tipuric had himself been given a start for Wales in the injury absence of Cardiff Blues' Wales captain Sam Warburton, who had been concussed in Wales' defeat by England at Twickenham the previous weekend.
Wales regular Jones was absent as Racing 92's Luke Charteris wore the his number five jersey alongside Wasps' Bradley Davies in the second-row.
More to follow.


Funding for the refurbishment of a closed halls of residence for Welsh-speaking students at Aberystwyth University could face uncertainty.

The university needs to ask the Higher Education Funding Council for Wales (HEFCW) for permission to apply for a loan to pay for work at Pantycelyn halls.
But a report said the university must attract more students before applying.
The university said work was continuing to ensure funding can be obtained.
Students climbed on to the roof of the halls last June to protest against the proposed closure, claiming the university did not value the Welsh language enough to keep it open.
A board was later set up to secure its future and Â£8m of improvements, including the refurbishment of 200 en-suite rooms, were suggested.
The university has said it planned to reopen the halls in September 2019, but the necessary funding needed to be secured before it could give a definitive commitment.
Now, a report to the university's council has been made public which confirms "HEFCW's agreement to procure such finance will only be forthcoming once the university has achieved the required sustained growth in student numbers".
It added the outcome of Brexit also threatened the future sustainability of the university.
The report continued that while the case for refurbishing Pantycelyn to provide Welsh-medium accommodation was "persuasive", the project must be considered in the context of others.
Other funding options suggested in the report include fundraising from individuals or trusts.
An Aberystwyth University spokeswoman would not comment on current recruitment figures, but said: "The university has stated clearly that Pantycelyn is one of its spending priorities.
"A team of Welsh-speaking architects has been appointed to work on the detailed plans for upgrading the building.
"In the meantime, work continues to ensure the required funding can be obtained, in line with the project timetable to reopen the building in September 2019.
"Loans are expected to be part of the funding of the university's priority capital projects. In common with all other universities in Wales, HEFCW's agreement will be required for any loan finance proposal of this scale.
"The university has not yet sought HEFCW's agreement for any loan."


Ben Osborn has already ensured his place in the history books at Nottingham Forest.

Anyone who scores a 92nd-minute winner against Derby County is pretty much guaranteed cult-hero status.
"It's all the fans know me for," he jokes, recalling the goal that beat the Rams in January last year and proved a memorable high point of Reds legend Stuart Pearce's time in charge.
The 21-year-old midfielder has been proving he has the substance to back up his stylish first Forest goal ever since.
And winning the Football League's Young Player of the Month award for January just confirms what many Reds supporters and manager Dougie Freedman have been saying.
"Scoring there was obviously a highlight," Osborn told BBC Sport. "It was a special moment to beat Derby away. But there have been a few others.
"When I first got in to the team it was amazing, and we were top of the league for a while at the start of last season."
Osborn's winner ended a miserable run and temporarily helped prolong Pearce's stay as manager.
But following Pearce's sacking, Derby-born Osborn has continued to flourish under Freedman, culminating in the Football League award that puts him alongside an illustrious list of previous winners including Dele Alli, Wilfried Zaha, Patrick Bamford and Victor Moses.
"I have never won anything like this before," he said. "It was a bit of a shock. I have seen some of the players who have won it and there are some great players.
"It's good recognition for the way I have been playing.
"I had a tough start this season with injuries and the illness but it is good to get back in the team and get a run of games. I have progressed and definitely got better, both physically and technically.
"I have been consistent and have added a couple of assists and a goal to go with that."
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Osborn's return to full fitness coincided with a fine run which saw Forest go 13 games unbeaten before Saturday's home defeat against Huddersfield Town.
He has made 23 appearances this season and started all five league games in January, scoring his first goal of the season in the 1-1 draw against Charlton.
Freedman has no doubt Osborn has played a vital part in Forest's climb up the table.
"He is crucial," said Freedman. "We lost Ben at the beginning of the season and not a lot was said about it.
"Ben is somebody that I have a got a lot of time for. He will be one of the first on the teamsheet if he continues like he has been in training.
"It's an award that is very well deserved. I am sure he will cherish it, but I am sure he will move on quickly and hopefully we will have more conversations about Ben winning awards."
Freedman feels Osborn has developed a great deal as he approaches the end of just his second full season.
"Ben's contribution has been fantastic, not just on the field but with the way he represents the club," added the 41-year-old Scot.
"He is fully committed with lots of heart. And of late he has started playing with his head and a bit more maturity.
"Ben has many, many assets but his main ones are his energy and wonderful left foot. He has a good passing range, a good temperament and has changed his off-the-field activities in terms of how he prepares and how he looks and studies the game.
"He has bought into a training regime that is very intensive, so is getting stronger.
"He is really coming on. He works hard every day and that attribute will get you places. He has a big future; he is an exceptional talent."
Osborn hopes his progression will help bring more players through the youth system at the City Ground.
And, given the financial restrictions because of Forest's transfer embargo, Osborn believes the next generation of youngsters could have a big part to play.
"The manager doesn't have to play me," he said. "There are probably bigger names but he has stuck with and I have come through. Hopefully it does inspire the other young lads.
"If the club doesn't have to spend money and can bring players through then it's a bonus for everyone and there's a better chance than ever to get in the team."


When the price of crude was riding high at about $120 a barrel, oil-rich countries seemed to have plenty of cash to go around.

Money was invested in shares and other assets around the world, not just by individuals, but by the sovereign wealth funds (SWFs).
But with the oil price sinking to around a 12-year low, there are signs that SWFs are having to dump assets to raise money. And that is exacerbating the turmoil on world markets.
SWFs are a bit like a savings account for a country, with money put aside for a rainy day. The money was spent buying shares, currencies, property or other assets.
But with oil hovering around $28 a barrel, it seems that day has arrived. There appears to be a fire sale of assets going on quietly in the markets.
It hasn't been a good start to the year for the financial world. There has been lots of selling, and when you have too much of something, naturally the price gets cheaper.
At the same time, China's economy is not growing as much as it used to. But the other major factor has been discreet selling by those who need cash quickly.
In particular, this means oil-rich countries which are finding shortfalls in their national coffers because the sale of their oil is not bringing in as much cash as it used to.
It is difficult to put an exact value on the assets held by sovereign wealth funds of oil-producing countries. The vast majority of them don't publicly say what assets they hold.
However, the general estimate of the worth of the top 26 SWFs has been put at about $4.5 trillion (Â£3.2 trillion).
According to eVestment, the data provider, at least $19bn was withdrawn by state institutions (or SWFs) during the third quarter of 2015. And that trend is set to continue this year.
These countries, relatively rich because of their natural resources, still have bills to meet and services to deliver.
And for countries such as Russia, which are facing a double whammy of sanctions and a recession, the most important thing is to get their hands on any cash they can. So that means selling their investments.
A similar picture is emerging from the oil-rich Gulf states. Saudi Arabia has just had to adjust its spending. In its last budget, it raised the price of water and electricity for households.
The danger for the sovereign wealth funds is deciding when and how much of their investment to sell.
If prices continue to fall, they might be forced to liquidate, which, as any market trader will tell you, is much worse than selling when you want to. Forced sellers could flood the markets - and that may trigger a crisis.
Simon French, chief economist at stockbrokers Panmure Gordon, said: "The current weakness in equity markets is the second wave of the commodity rout. First, it was the valuations of the miners and oil and gas majors being marked down.
"This second wave is being led by the governments of countries dependent on commodity revenues. They built up equity portfolios in the good times and are raiding these 'rainy day funds' to balance their 2016 budgets."
It is believed that Blackrock, Aberdeen Asset Management and JP Morgan are among some of the financial institutions that have seen outflows from sovereign funds last year.
Some of the SWFs have made poor investment decisions and consequently, their worth has fallen.
Qatar was one of the biggest investors in Volkswagen, and since the emissions scandal, the German car company's share price has fallen substantially.
Ratings agency Moody's has carried out its own report, called Sovereign Wealth Funds: Sizeable Assets Provide Important Fiscal Buffers Against Lower Oil Revenues.
The agency says 73% of sovereign wealth fund assets globally are funded from oil and gas export revenues.
Elena Duggar, author of the report, said: "As oil prices remain lower for longer, fiscal and current account balances of oil exporters will be under increasing pressure. As a result, we expect increasing use of sovereign wealth fund assets to finance budget deficits and support domestic economies."
The sell-off has been relatively controlled for the time being. But if the price of oil remains low, the sell-off will intensify and start hitting sectors such as banking.
And that looks pretty grim for the rest of us, as it's our pensions and savings that are invested in those shares.
A crisis of sorts is brewing.


Hundreds of people have attended a rally in Ballymena calling for investment to bring new jobs to the town.

Almost 2,000 people will lose their jobs when Michelin and JTI Gallaher close within the next two years.
Liam Neeson, who is originally from Ballymena, has lent his voice to the campaign.
A message from the Hollywood actor was played to the crowd on a big screen on Saturday.
He told them "this is the start of the fight back".
Other speakers at the event asked for politicians at Stormont to take note that they want manufacturing jobs brought back to Ballymena.
One 17-year-old told the crowd she had no option but to leave her home town in search of work.
"Stormont aren't recognising us as a town worthy of investment," Shealyn Caulfield said.
"They need to get off their backsides and put some energy and put some hope and life back into a town that we love so much.
"We look towards our politicians and our leaders to care for us, but all they're doing right now is covering their tracks from the past and fighting about it and they're so engrossed in it."
The rally was organised by the Unite union.
The union's Irish regional secretary Jimmy Kelly said thousands of well-paid and well-organised jobs were being lost and that a community spirit had developed within the workforce at the two factories.
"What we didn't want to do was this day next year talk about how terrible it is," he said.
"Young activists here in Ballymena wanted to do something, wanted to fight back, wanted to declare to politicians that they've got to get the investment and build a future here."
Last November, it was announced that the Michelin tyre factory in the town would close in 2018 with the loss of 860 jobs.
It was the second major jobs blow to the town in just over a year.
In October 2014, cigarette maker JTI Gallaher announced it would be shutting its plant in the town with the loss of 800 jobs.
Redundancies there are expected to begin in May 2016 and the factory will shut down completely in 2017.


UK intelligence needs to do more to recruit middle-aged women and mothers to be spies, using websites like Mumsnet, according to senior MPs.

In a report, the Intelligence and Security Committee (ISC) said such women were an "untapped recruitment pool" for MI5, MI6 and GCHQ.
It said more than half of the civil service were women, but the figure was 37% in the intelligence agencies.
Hazel Blears, the Labour MP who led the report, called for a culture change.
Women make up 53% of all civil servant roles but the report found that in the three intelligence agencies there are "disproportionally more" female members of staff at junior grades, with only 19% reaching senior grades.
The report said women should not be limited to certain jobs.
Ms Blears said: "I personally want women to be attracted to a career in intelligence and to feel there is the prospect of real advancement."
Speaking to BBC's Woman's Hour she said things are improving but are still not good enough.
She said "We need to keep using women's skills and experience.
"If you have been running agents in Afghanistan, you are a really valuable resource.
"It is absolutely crucial that after you come back having had children that you don't go into something like HR or finance."
Ms Blears claimed there could be an issue for women with children when MI6 officers needed to travel abroad.
She said: "There is a bit of testosterone in the system that says 'tickets, money, passport - we all have to get there'.
"And if you've got children, finding 24-hour childcare is often very difficult.
"I feel quite strongly that the agencies can plan better, even for emergencies, you can have plans in place, you can have childcare providers."
Ms Blears said some female recruits at MI6 had complained about the attitudes they encountered within the service.
One female recruit told the committee that she thought the organisational culture was male dominated.
She said: "I was told once during training that I could have used my 'womanly charms' to build rapport by a role player, which I found very frustrating as I wondered what my male colleagues did to build rapport without such charms."
A government spokesman said it was determined to increase the number of women in the security and intelligence agencies, particularly at a senior level.
He said: "The agencies have made good progress, which is acknowledged by the ISC, and clearly demonstrated by the representation of agency boards and by the increasing availability of operational roles with flexible working patterns.
"We are committed to ensuring the most talented people succeed and reach top positions, regardless of gender, ethnicity, sexuality or disability, and will report to the ISC by 2016."
Former US Secretary of State Madeleine Albright praised Ms Blears' three-year investigation and said it echoed work she had done at the CIA.
She said: "Diversity should be pursued - not just on legal or ethical grounds - but because it will result in a better response to the range of threats that threaten national security."
Mumsnet chief executive Justine Roberts offered a tongue-in-cheek response to the suggestion that the parenting forum was a suitable place to recruit female spies.
Referring to Cold War spy tactics, she said: "I'm afraid I'm unable to comment as I have an urgent appointment with a rock in St. James's Park."


As a team of archaeologists digs through layers of history beneath London, the thought of the next find is never far away.

"Just about any new discovery is thoroughly exciting," says Jay Carver, the lead on what is currently the UK's largest archaeology project.
His team has been working alongside engineers building stations and digging two giant tunnels under central London as part of Crossrail since 2009.
On the journey so far, finds include rare amber, hundreds of skeletons and a Bronze Age track.
But for Mr Carver, among the most exciting discoveries was the Thames ironworks and ship building company which occupied the entire Limmo Peninsula.
He said: "The site had literally been forgotten in the ground. It was 100 years old but we have pretty much been able to reconstruct it.
"To have discovered this huge timber shipway was extraordinary.
"The discovery of ancient animal bones in Paddington takes it to the other extreme to a London with wild animals, an unbelievable concept in today's world."
Crossrail will connect 37 stations from Heathrow Airport and Maidenhead in the west, through central London and out to Abbey Wood and Shenfield in the east.
It is due to be completed in 2018.
Being a part of this giant feat of engineering has allowed the 100-strong team of archaeologists to venture into largely unexplored territory.
Mr Carver said: "The project has allowed us to dig so many holes across so many parts of London.
"It's about filling information gaps, finding out about stuff we didn't know before and making all the details we had in the past, clearer."
He explained that digging from west to east through the centre of London, which due to city's built-up nature is usually restricted, gives them a unique opportunity.
"It enables us to compare and contrast areas of London by gathering scientific data from different locations, for example excavating several sites across west London and parts of the City.
"Looking at how they developed from green fields into the city we know today and how the river system changed and developed over thousands of years.
"It will also reveal thousands of years of history in the Square Mile which covers what was a Roman and medieval city, which are fairly unknown."
Advances in technology may mean there is less uncertainty about what might lay beneath the surface, but Crossrail has still delivered a few surprises.
At Canary Wharf a 55-million-year-old piece of amber was unearthed from beneath the dock bed in 2009.
The archaeology team said very little amber had been found in London and this piece was larger and clearer than any previously found in the UK.
The next stop for the team is Farringdon where archaeologist Mike Court will be leading a two-week excavation in January.
Trial digs have confirmed an old river channel and evidence of leather production under Smithfield Market.
Mr Court said: "It is exciting as you spend years doing the research then you get to dig and prove your homework."
"It's close to a big plague pit from the black death so it gives us a chance to dig down but there's only a 20% chance we will find it."
Meanwhile, in a trial excavation pit at Liverpool Street in February 2011, Mr Court said they came across what he considers to be the most exciting find on the project so far - a silver Denarius, a Roman coin from 225AD.
"It's fairly run of the mill for sites but it gives you something in your hand which showed the time Britain was part of the Roman Empire and puts us into the wider context," he said.
Looking to 2013, Mr Carver said they would be working on the largest single excavation at the site of Crossrail's ticket hall in Liverpool Street.
It is expected to reveal the less salubrious parts of Roman London outside of the City walls with archaeologists anticipating to encounter Roman timber-framed buildings and a street surface 6m below ground level.
The "lost" Walbrook River - a channel that divided the western and eastern parts of the city -  may also be found.
At the eastern end of the Crossrail route, archaeologists will work at four large tunnel entrance sites at Pudding Mill Lane, Victoria Dock, North Woolwich and Plumstead.
Here it is thought the team will come across areas where Bronze Age people lived, farmed and hunted some 3,500 years ago.
Only halfway through its journey, and with a total of 20 archaeology sites to explore, it is hoped there is much more to be uncovered.


Great Britain finished second at the European Cross Country Championships as they narrowly missed out on topping the medal table for a 14th year in a row.

Gold and silver for Turkey in the final race - the men's seniors - put them just ahead of Britain, who were helped to team gold by Callum Hawkins' bronze.
Steph Twell's earlier sixth saw Britain win team silver in the women's race.
Britain won team gold in the women's under-20 and under-23 races, and bronze in the men's under-20 and under-23s.
And there was individual medal success for Harriet Knowles-Jones, Mahamed Mahemed and Alice Wright.
Find out about how to get into running with our special guide.
Knowles-Jones won bronze in the women's U20 race, Mahemed took bronze in the men's U20s and Wright finished third in the women's U23s, with Charlotte Taylor taking fourth.
But it was not quite enough to beat Turkey, who finished with three golds, two silvers and one bronze to Britain's three golds, one silver and six bronzes.
Turkey's 19-year-old Kenya-born Yasemin Can, the 10,000m and 5,000m European champion, won the women's senior race ahead of compatriot Meryem Akda, who was also born in Kenya.
Karoline Bjerkeli Grovdal of Norway was third, with Twell the highest-placed Briton in sixth place, Gemma Steel 12th and Katrina Wootton 16th.
Two Kenya-born Turks also dominated the men's senior race, with Aras Kaya taking gold and Polat Kemboi Arikan silver ahead of Hawkins, while GB team captain Andrew Butchart came fourth and Andy Vernon fifth.


Heavy rain and winds as high as 100mph (160kph) are battering parts of the UK, causing floods and disrupting travel.

Homes and businesses were evacuated and hundreds have been left without power.
In England, there are more than 90 flood warnings, mainly in the South West, the Midlands and East Anglia, and there are also 14 flood warnings for Scotland, mostly in Tayside.
Gales have been reported on the Welsh coastline with even stronger winds reported inland,
The Met Office has warned there is worse to come.
There are also nearly 200 alerts for possible flooding in England and Wales.
Amber "be prepared" warnings for heavy rain have also been issued across much of south Wales, and in south-west England where a joint command structure has been set up by rescue services.
In Scotland, the warnings for expected flooding also cover the Borders and Dumfries and Galloway - as rainwater filters down from the hills.
An amber warning for heavy rain was issued for much of Strathclyde, Dumfries & Galloway, Stirling, Perth & Kinross and the southern Highlands. And the River Nith in Dumfries is flooding for the second time in a week.
In other developments:
The Met Office says the wet and windy weather will move east across England and Wales overnight, leading to clearer conditions in most areas. But rain will continue to affect the south-east and north-west of the UK into Friday morning.
But the Environment Agency warned rain falling on already saturated ground could lead to further river and surface water flooding.
John Curtin, head of incident management, said: "We ask that people stay safe by staying away from swollen rivers and not attempting to drive through flood water."
Wind speeds have risen in north-west Wales and gusts of 70mph have been recorded at Capel Curig.
Unofficial wind speeds of 100mph have also been recorded on Snowdon, Gwynedd, and 92mph at Worm's Head on the Gower peninsula.
In Wales a fallen oak tree narrowly missed a house in New Quay, Cardigan Bay, where a "massive crash" was heard at 05:30 GMT.
From the BBC:
Elsewhere:
In Northamptonshire about 1,000 people had to leave their holiday homes at Billing Aquadrome, alongside the River Nene.
On the railways, services between Devon and Somerset were badly affected with the worst flooding impact for five years.
Twelve separate areas of track were impassable and the line was likely to be closed for the next two days, said a First Great Western spokesman.
Arriva Trains Wales said all services in north Wales were either cancelled or delayed due to flooding between Holyhead and Llandudno Junction.
In Cumbria, TransPennine Express said it could not operate any train services to or from Barrow because of "severe" weather conditions.
BBC trainee Ross McCoughlin, 23, has been staying at the Northwick Hotel in Evesham, Worcestershire, and said floodwater meant guests were "stuck".
He said: "When I came down to breakfast the road was gone and it's now a river. It was quite a shock seeing ducks coming up to the front door."
In Kent, the RSPCA criticised a decision to allow hundreds of sheep to travel on a ship which had to turn around due to bad weather.
The ship, the Joline, had to return to the port of Ramsgate, and as the animals were taken off in two lorries they were greeted by angry protesters who condemned the decision to sail amid concern for the animals.
A canoeist had a narrow escape after being caught in bad weather near Burgh Island, off the south Devon coast.
Dave Scullion, watch manager at Brixham Coastguard, said: "We strongly advise not to go out in these stormy conditions, particularly in small craft such as canoes or kayaks.
"Sending units to rescue people in these types of avoidable incidents will put the rescue teams at risk."


The British-led effort to break the World Land Speed Record is going to slip again - to 2018.

The Bloodhound Super-Sonic Car was supposed to go racing later this year, to try to raise the current mark of 763mph (1,228km/h) to over 800mph.
But what are described as "short-term cash flow problems" have put a dent in the schedule.
The upside, says the team, is that it provides additional time to eke more power from the car's rocket.
Engineers want some extra thrust margin just in case the final build of the vehicle turns out to be heavier than expected.
"It's frustrating, I know; and the team are disappointed but we're resilient and we're going to make this happen," Bloodhound director Richard Noble told BBC News.
"The money is coming in but it doesn't always match our planning and fit with the times when we need it."
In the meantime, the project's education programme, which delivers STEM activities to schools, continues apace. Nearly 100,000 children have participated in the last year, developing their knowledge of maths and physics by constructing and running mini rocket cars.
Bloodhound has signed some big sponsorship deals recently, notably with the Chinese auto manufacturer Geely. This cleared all debts.
Mr Noble said he was also in the process of inking two more - one with a major IT company, and another with a leading fashion brand.
But the time it takes for deals to be agreed, for contracts to be signed, and for money then to flow sometimes leaves Bloodhound cash-short, he explained.
"I'm reasonably happy now that we'll be able to make our budget this year, which is great - and that means we will be on the desert, running the car, probably in mid-summer 2018."
The car itself is all but finished. It was put on static display in October 2015, and then stripped down for a final re-assembly, with fluids, and checks.
The plan now is for Bloodhound to do its slow-speed testing (about 200mph) on the runway at Newquay Aerohub in late summer/autumn this year.
A specific date has yet to be announced but it will follow the completion of some "tie down" investigations, in which the car is held in place while its EJ200 Eurofighter jet engine is taken up to speed.
The jet is what will get the car rolling for its assault on the land speed record when it eventually gets to the race track on Hakskeen Pan in Northern Cape, South Africa. But it is the grunt from a rocket that will push the vehicle through the sound barrier and up to 800mph.
Bloodhound's partner on this is the Norwegian aerospace and defence company Nammo.
It is providing in the first instance what is termed a monopropellant rocket. Monopropellants work by pumping High Test Peroxide over a catalyst. This decomposes the liquid to produce super-hot steam that is then vented through a nozzle.
Nammo has been testing rockets that have produced 30 kilonewtons of thrust. But Bloodhound's engineers would like to get closer to the rockets' expected monopropellant thrust ceiling of 40-45kN.
This would yield some margin in performance if the final assembly of the car turns out to be significantly heavier than the anticipated 7.5 to 7.75 tonnes.
"The car's weight has fluctuated between 200 and 500 kilos from where we thought we were going to be. It's something of a moving feast; we're weighing the car as we're building it," said chief engineer Mark Chapman.
"But if the figures turned out to be pessimistic, we'd look pretty stupid if we turned up at Hakskeen Pan and could only do 680mph. So, the thought was: let's be sure we can get to the speeds we want.
"Nammo are confident they can deliver a 45kN motor. They'll test that motor later this year and then we'll test it in-car next year."
The Bloodhound project was launched in 2008. Back then, the thought was a new record bid would be made in 2011. But the scale of this land speed attempt has dwarfed all previous efforts.
Richard Noble was the director for the Thrust SSC car when it set the current world record in 1997. He says just Â£2.48m in cash was spent to achieve its supersonic mark.
In contrast, the cash spend on Bloodhound is likely to be in the region of Â£60m. On top of this are a whole host of in-kind contributions, which include the loan of EJ200 engines from the Ministry of Defence and the consultancy work that comes with them from Rolls-Royce.
The companies and scientific institutions involved all speak of a "Bloodhound effect".
The two universities - Swansea and the West of England - who helped to design the car say there has been a big rise in the numbers applying to take their aerospace and engineering courses.
Likewise, engineering firms such as Castle in Glasgow, which has made the aluminium wheels for Bloodhound, say they have found it much easier to attract apprentice applications - a boost it attributes directly to the Bloodhound association.
Jonathan.Amos-INTERNET@bbc.co.uk and follow me on Twitter: @BBCAmos


A former police officer who crashed into two cars while running a red light on an emergency call-out has won a court battle to overturn a driving ban.

Natasha Watt, 23, was originally given a 12-month disqualification after she admitted dangerous driving.
She collided with the vehicles after being called out to help colleagues who were under attack in Aberdeen.
The police constable activated the blue lights on 20 November 2014 despite having no emergency response training.
Appeal sheriffs have now quashed the Aberdeen Sheriff Court ban, and given her five penalty points.
Watt, of Kintore in Aberdeenshire, had only passed her test eight months before the crash.
She later resigned from the police service.


Online retailer Amazon has apologised for selling doormats featuring the Indian flag on its Canadian website.

Amazon removed the product from its website on Wednesday, and apologised the following day after Indian Foreign Minister Sushma Swaraj's strong criticism of the firm.
Ms Swaraj had tweeted that India would rescind current visas for Amazon officials if it failed to apologise.
Desecration of the flag is punishable with fines and imprisonment in India.
Fury over India flag doormats on Amazon
Amazon drivers 'work illegal hours'
Amazon's India vice president, Amit Agarwal, said in a statement that his firm was "committed to respecting Indian laws and customs".
"A third-party seller, not Amazon, had listed these products for sale in Canada... Amazon regrets the same. At no time did we intend or mean to offend Indian sentiments," he said.
In a series of tweets, Ms Swaraj had asked the Indian High Commission in Canada to take up the issue with Amazon after it was brought to her attention by another Twitter user.
"Amazon must tender unconditional apology. They must withdraw all products insulting our national flag immediately," she said.
"If this is not done forthwith, we will not grant Indian visa to any Amazon official. We will also rescind the visas issued earlier."
Last June Amazon found itself in a similar controversy over sales of doormats illustrating Hindu gods.
The row comes as Flipkart, India's biggest online retailer, is involved in a fierce battle with Amazon over market share.


Victims of the last Luftwaffe attack of World War Two to cause civilian casualties in the UK have been remembered at a ceremony, 70 years on.

Thirteen people were killed and 22 injured when a lone Heinkel 111 bomber flew along Holderness Road in Hull on 17 March 1945.
The crew opened fire with machine guns and dropped fragmentation bombs.
Many of the dead and injured were just leaving the Savoy cinema at the end of a film performance.
Source: A North-East Coast Town - T Geraghty
Listen: Neville Chamberlain announces war with Germany
How British solidarity grew through the terrifying blitz
The victims are commemorated on a plaque on the site of the cinema.
No high explosives were used, so no structural damage to buildings was done.
"It was the last Luftwaffe attack on the UK that killed civilians." said local historian Ron Fairfax.
"There is no trace in the German archives of the attack and anecdotal evidence suggests it was a maverick crew intent on revenge for the devastation wrought by an Allied air raid on Dresden a few weeks earlier".
The aircraft was unopposed as local RAF squadrons had been transferred, anti-aircraft installations had been moved south and the home guard and wartime emergency services had been stood down.
The attack was reported at the time as 'an attack on a north east coast town' because of a censorship notice imposed on information from the city.
During the course of the 1939-45 war 1,200 people were killed and a further 3,000 injured in the city.
Councillor Mary Glew, the city's lord mayor, attended the ceremony at the plaque.


Jeremy Corbyn said on Thursday: "The Labour Party's overwhelmingly for staying in."

That's clearly true among Labour MPs. The vast majority of them are backing Remain, with only eight supporting leaving the EU.
But what about the wider party and its supporters? Kate Hoey, one of the Labour MPs who backs Brexit, claimed that beyond Westminster the picture was different. "We are in a minority in Parliament but we're not a minority in the country in terms of Labour supporters."
So who is right?
Looking at opinion polls it seems that it's the party leader. All polls on the EU referendum break down voters by voting intention or how participants voted at the General Election. In any single poll, the number of Labour voters is probably too small to draw firm conclusions, and there will always be uncertainty about the precise figures, but over many polls a clear pattern emerges.
In the last 10 published EU referendum polls the figures for Labour voters break down as:
Remain: 60%
Leave: 26%
Don't know/won't vote: 14%
(Sources: BMG, ICM, Opinium, ORB, TNS, YouGov)
Excluding "don't knows" that makes it 70:30 in favour of Remain. The equivalent figures for Conservative voters are 54% to 44% in favour of Leave.
There was also one poll in February of Labour Party members and registered supporters. That reported an even more one-sided picture: 81% for Remain, 11% for Leave, with 8% unsure. Again, we should treat the precise figures with caution but it's a pretty emphatic result.
(YouGov, 11-15 February 2016, sample: 1,217 Labour Party members and registered supporters)
Reality Check verdict: We have all learned to be suspicious of polling data, but it seems Jeremy Corbyn is right that he leads a party whose members and supporters back Remain by a large margin.
Read more: The facts behind claims in the EU debate


World number one Novak Djokovic has been knocked out in the third round at Wimbledon by American Sam Querrey.

The Serb admitted he "wasn't really 100%" going in to his match, which stretched out over two days because of rain delays.
Djokovic, who has already won the Australian and French Open this year said he was hurt by his exit, but added: "I managed to win four Grand Slams in a row over two different seasons. I want to focus on that rather than on failure."
It was his first defeat in a Grand Slam third round for seven years.


Anglers in Wales have been asked to release all the salmon they catch in a bid to conserve fish stocks.

Natural Resources Wales (NRW) made the "urgent" request and described the number of salmon in Welsh rivers as "cause for serious concern".
Habitat damage, pollution and illegal exploitation have put additional pressures on fish stocks, it said.
Dave Mee, senior fisheries advisor for NRW, said the survival of salmon at sea was at an "historic low".
He added: "Most anglers are already voluntarily releasing the fish they catch but we feel the situation is now so serious for salmon that we must ask all anglers to release all of their salmon.
"Anglers releasing their fish is one of the most effective way to help safeguard our stocks by allowing more fish to survive and spawn."
An annual assessment of fish stocks in 2016 showed all but two - the Severn and Usk - of the 23 salmon rivers in Wales were "at risk" or "probably at risk".


Former football coach Barry Bennell has pleaded not guilty to eight charges of sexual assault against a boy under 16.

The former youth coach at Crewe Alexandra denied the eight counts when he appeared at Chester Crown Court.
The charges all relate to allegations of abuse between 1981 and 1986.
Mr Bennell, 63, wearing a blue polo neck shirt and appearing via videolink from HMP Woodhill, in Milton Keynes, answered "not guilty" to all the charges as they were put to him.
The ex-coach, who also worked at Manchester City, Stoke City and junior teams in north-west England and the Midlands, was remanded into custody until 20 March.
Owen Edwards, prosecuting, told the court the alleged victim "preserves his anonymity".


A silicone object left inside someone, a patient falling from a window and the wrong person undergoing an exploratory procedure are among "never events" which have happened in Welsh hospitals.

These are "largely preventable patient safety incidents" that should not happen if proper measures are in place.
There were 60 of these incidents in Wales' seven health boards from April 2012 to present.
The Welsh Government said: "Patient safety in Wales is paramount."
Items mistakenly left inside patients following surgery or procedures include vaginal swabs, a surgical blade and a silicone object.
Wrong site surgeries included the wrong joint being injected, the wrong side pleural biopsy, operating on the wrong spinal disc and the incorrect tooth being removed.
Incorrect implants or prosthesis included a hip replacement, a lens and a pacemaker.
One person was also able to fall from a window which was within reach of patients at floor level and could be opened without the use of a tool.
A Welsh Government spokesman said: "Every year, hundreds of thousands of people receive high-quality, safe care in the Welsh NHS.
"However, in an increasingly complicated and modern healthcare system, problems can unfortunately happen.
"When problems do occur, NHS staff are encouraged to report all incidents so they can be investigated openly to promote learning and provide open feedback to patients and their families as part of our commitment to an open safety culture."
Between 2012 and 2016, Abertawe Bro Morgannwg health board had 15 "never events", Aneurin Bevan had eight, Betsi Cadwaladr had 15, Cardiff & Vale had 13, Hywel Dda had four and Cwm Taf had five. There were none in Powys.
NHS Wales publishes an annual list online of all the mistakes made.
Abertawe Bro Morgannwg
Aneurin Bevan
Betsi Cadwaladr
Cardiff & Vale
Cwm Taf
Hywel Dda


The US has imposed duties on Chinese solar panel manufacturers after it said that they received unfair subsidies.

Chinese exporters into the US - including Suntech - will now face customs tariffs of between 2.9% and 4.73%, the Commerce Department said.
In 2011, imports of solar cells from China into the US were valued at $3.1bn (Â£1.96bn), it added.
The price of solar panels dropped more than 30% last year, mainly linked to cheaper panels made in China.
"Countervailable subsidies are financial assistance from foreign governments that benefit the production of goods from foreign companies," the Commerce Department said.
China's Suntech, the world's largest producer of solar panels, will now face duties of 2.9% to offset what the US said is its subsidy from the Chinese government.
Another firm, Changzhou Trina Solar Energy, will receive duties of 4.73%.
All others face duties of 3.61%.
US customs will collect deposits equivalent to these amounts now and the Commerce Department will make a final ruling in June.
The US will also rule on whether China's solar panel output is violating its anti-dumping rules on 17 May.
Chinese firms have said that they are not the only ones that receive government help - for example, the US has subsidies to encourage people to install solar panels.
China has already said it will launch its own investigation into US government support for renewable energy.


Malaysian football star Mohd Faiz Subri has taken home Fifa's prestigious Puskas Award for the best goal of 2016, a first for his country.

The 29-year-old from Penang secured nearly 60% of the popular vote for his free-kick in the Malaysian Super League against Pahang state in February.
He was presented with the trophy by Brazilian football legend Ronaldo.
Others in the running included players like Marlone and Venezuelan midfielder Daniuska Rodriguez.
Also at the inaugural ceremony, held in Zurich, Cristiano Ronaldo was named the world's best player, beating old rival Lionel Messi to the title.
Faiz, who plays with the Penang FA team, spoke of his surprise at his win and dedicated the prize to his family, friends and country.
"I'm extremely happy because I didn't expect it at all, I'm certainly shocked because this is the biggest award I have ever won in my career," he said.
"The secret to my success is to be disciplined in my training. I'll continue to focus on competing in this year's Malaysia Super League."
The win has resonated with football supporters and other Malaysians back home in the South East Asian nation.
"Faiz is now a world icon thanks to his ability," said Penang Football Association Team Manager Zairil Khir Johari.
"It's an amazing and well-deserved achievement, not only for Faiz but for football in Malaysia as a whole," he said.
He added: "I am confident he will now inspire a whole generation of footballers in our country."
Other Malaysians began expressing joy and pride for their "national hero" and shared congratulations for his achievements.
"Without or without our votes he deserved to win and did us proud," wrote Hafiq Hasan Basri from Kuala Lumpur.
Saegaran Kana remembered the moment as "an astounding goal". "Thanks for honouring Malaysia," he added.
"Faiz has made us all proud. It is an honour to all Malaysians when the world's top football players give their respect upon an incredible home feat," said Mohd Sukhimi.
"What an incredible milestone for Malaysia. I haven't even gotten over that crazy goal yet," said Elaine Loh in a Facebook post.
Additional reporting by Woon King Chai in Kuala Lumpur.


A third osprey chick has hatched at a mid Wales nesting ground days after the first emerged from its egg.

The eggs were produced by the mating pair Monty and Glesni, who have previously produced four eggs in the last three years.
This batch of eggs was first spotted at the Cors Dyfi nature reserve near Machynlleth in Powys on 25 April.
The first chick hatched last Friday, with the second appearing on Sunday followed by the third late on Tuesday.
It was the first time Glesni had laid three eggs, the Dyfi Osprey Project said. The chicks have been named Bob 1, 2 and 3.
Another nesting pair in the Glaslyn Osprey Project, near Porthmadog, is currently incubating two eggs


Scottish Green Party co-convener Patrick Harvie said his party might not be able to support the SNP government's draft budget.

The minority administration could require backing from opposition MSPs to implement its proposed plan.
The nationalists might have expected support from the Greens, which backs Scottish independence.
However, Mr Harvie said the budget failed to have a "progressive approach" to taxation.
He told BBC Radio Scotland's Good Morning Scotland programme that the SNP "needed to give some ground" and "move some way towards some other party" if it was to win backing for its budget.
Mr Harvie suggested that higher earners "could pay a bit more" if the government chose to reduce the threshold of the higher rate of tax.
In April, Holyrood will receive the power to set the rates and bands of income tax on non-savings and non-dividend income.
The Scottish government has already said it would not replicate Westminster's plan to increase the starting point at which workers in England, Wales and Northern Ireland pay the 40p tax rate.
However, it will allow that threshold to increase by the rate of inflation.
Mr Harvie disagreed with that approach and called for the government to cut the starting point for paying the 40p rate.
He explained: "They [Scottish government] could change the threshold in the higher rate.
"They are proposing to increase that, not by as much as the UK, but still increasing it - that represents a tax cut for high earners."
He urged Scotland's Finance Secretary Derek Mackay to reduce it instead and "that would mean what high earners have gained gets clawed back and invested in public services".
Derek Mackay needs opposition support for his tax plans and his budget - preferably via members voting for them, but if necessary just by them abstaining and not standing in his way.
The finance secretary has been holding detailed talks behind the scenes with opposition leaders, with the Lib Dems and Greens seen as the most likely candidates for a deal.
You can more or less forget about the Conservatives and Labour; neither of them will buddy up with the SNP with hard-fought council elections looming.
It's now looking more and more like you can count the Greens into that same category.
Patrick Harvie took Mr Mackay to task over tax in this week's finance committee meeting, and has now doubled down on that position on Good Morning Scotland.
But Derek Mackay isn't likely to budge on tax. Some bits of spending, maybe, but not tax.
Negotiations will continue in earnest, but these latest developments might leave Willie Rennie as the best placed to strike a deal with Mr Mackay.
He too will have concerns about tax and local services in particular, but it's possible he could be won over with extra funding for mental health and education.
When Mr Harvie was asked by radio presenter Hayley Millar whether his party would be backing the draft budget, he replied: "I don't think we can support a budget that has such astonishing cuts to local government services - local services are the ones that people rely on day in day out.
"We need to be investing in those services and protecting the well being of the people who are delivering those services who suffered year after year of real terms pay cut."
Mr Harvie also reiterated his party's support for Scottish independence.
He added that "no one" expected a second referendum on the issue to take place this year, but he believed "it should remain on the table".
Mr Harvie said: "Maybe at some point around the half way mark of the two-year Brexit negotiation period, or not long after that half-way mark, we might need to be in a position to put that question [about Scottish independence] to the public."


An Argentine prosecutor has accused Iran of trying to infiltrate countries in Latin America to sponsor and carry out "terrorist activities".

Alberto Nisman said Iran was attempting to set up intelligence-gathering stations in Brazil, Chile, Colombia, and other countries in the region.
Mr Nisman is investigating a bomb attack that killed 85 people in a Jewish centre in Buenos Aires in 1994.
Iran has always denied involvement in the attack.
But in an indictment handed to a federal judge in Buenos Aires on Wednesday, Mr Nisman repeated the often-made claim that Iran sponsored the bombing.
And he accused Iran of a nefarious project in the wider region.
"I legally accuse Iran of infiltrating several South American countries to install intelligence stations - in other words espionage bases - destined to commit, encourage and sponsor terror attacks like the one that took place against Amia," Mr Nisman was quoted as saying, referring to the Jewish centre bombed nearly 20 years ago.
He said the countries targeted included Brazil, Paraguay, Uruguay, Chile, Colombia, Guyana, Trinidad and Tobago, and Surinam.
And he claimed that Mohsen Rabbani - the Iranian former cultural attache in Buenos Aires who Argentina blames for the Amia attack - was co-ordinating the alleged infiltration operation.
In February Argentine legislators approved an agreement with Iran to set up an international truth commission to investigate the Amia attack.
The Argentine government proposed this commission as a way to reactivate investigations into the bombing, but the opposition and some Jewish groups in Argentina have criticised it.
Argentina has issued arrest warrants for several Iranian nationals and a Lebanese national in connection with the bombing.


A Hillsborough survivor has found the "hero" who pulled him from the crush as an eight-year-old boy.

Joe Smith, 35, launched a Facebook appeal after seeing himself on the shoulders of his rescuer while watching a BBC Two documentary.
Mr Smith said the response had been "absolutely phenomenal" and "beyond anything I could have imagined" after the post was shared 145,000 times.
The pair have since been in contact and are now arranging to meet.
Mr Smith, from Kirkby in Merseyside, said: "He's a guy I've always had in my thoughts and I've always spoken about when people ask me about my experiences.
He said the man, who wishes to stay anonymous, "couldn't get his head round the fact I said he was a hero".
"He said he was just a normal fellow, and I said 'well you are mate get used to it'," he added.
Mr Smith had travelled with his stepfather and brother to watch Liverpool play Nottingham Forest in the FA cup semi-final on 15 April 1989.
Inquests last month concluded 96 fans who died in the crush were unlawfully killed.
Mr Smith said his legs were being crushed as he stood at the Leppings Lane end of Sheffield Wednesday's stadium, and his stepfather lifted him to get him out.
He was passed over people's heads and taken to the other end where fans looked after him.


A Canterbury hockey player hopes to be chosen for the Great Britain squad for London 2012.

Natalie Seymour is one of the 32 women competing for one of just 16 places in the Olympic hockey team.
The women are training together on a full-time basis at Bisham Abbey National Sports Centre in Buckinghamshire. Competition is fierce but they have a common goal.
"We are all pushing each other, which is great because the competition for places will only make the best team go to London and that's really what we are all aspiring to," said Seymour.
"We are in an environment where we are used to selection and when you don't get selected for things it's really tough. But we have to be safe in the knowledge that the coaches are going to pick the squad that they think will win a medal in London.
"While you will be disappointed, there will be a period of time when you go in and train and help the guys out that are going. It's something we work on with our psychologist."
A SPORTING FAMILY
Seymour, 24, grew up in Maidstone and went to Boughton Monchelsea Primary School and then Maidstone Grammar School for Girls.
From a young age, she became involved in various different sports but at the age of 13 chose to focus on hockey.
The opportunity to perform at an Olympic Games at your home country - it just doesn't get any better than that.
"It's just great being part of a team and the opportunities of playing a fast skilful game," she said.
"Hockey combines all aspects of fitness - you've got the skill related stuff but you've also got the health-related fitness in terms of speed and you need to be strong and fit so it's really good."
Seymour comes from a sporting family and has two sisters who have also been involved in sport. Her eldest sister, Louisa, used to be part of the England rugby set-up. Her family have always strongly supported her ambition to excel at her sport.
She said: "I can remember days when my mum would drive me around the county to various hockey events.
"When I was doing all the sports under the sun, she drove me from a netball tournament to a hockey game then back to a swimming gala in the evening."
"Having that kind of support as well as the emotion support is invaluable."
GETTING SELECTED
So how confident is Seymour that she will make it to London 2012?
"You have to go into every day believing you are going to be part of that squad. Every single one of us wants to be in a team that is winning medals in London 2012.
"The thought of that gives me goosebumps but right now I'm just trying to focus on those day-to-day processes. If you look too far ahead, you won't do the right thing now."
The all-important selection date is towards the end of June, which seems late considering the games begin in July. But as the decision is based on performance, Seymour believes the players that form the best, balanced team at the time will be the ones to go.
The team that is selected should have a good chance of bringing medal home, according to Seymour.
"It's an exciting thing to be involved in and you've got the support around you of other people going through exactly the same thing and it's a great thing to share.
"When the going gets tough there's always someone there to pick you up. You are making sure you are doing best for the team, not just for yourself."
So, what would it mean to win a place in that Olympic team?
"It would just be a dream come true.
"It's been a goal of mine for so long to be part of successful international teams and the opportunity to perform at any Olympics is priceless.
"But the opportunity to perform at an Olympic Games at your home country - it just doesn't get any better than that."
Natalie Seymour is one of BBC Radio Kent's three featured athletes as part of 'Olympic Dreams' in the build-up to London 2012.


Troy Deeney scored a second-half penalty to equalise for Watford as Sam Allardyce took a point on his return to management with Crystal Palace.

After dominating in the opening stages, Palace went ahead through Yohan Cabaye's low strike in the 26th minute.
The visitors missed the chance to double their lead when Christian Benteke's penalty was saved by Heurelho Gomes after the Watford goalkeeper had fouled the Belgian.
Deeney converted his penalty - after Sebastian Prodl was fouled - to end a 10-game goalless run and score his 100th Watford goal.
The point for Palace, who sacked Alan Pardew as manager on Thursday before appointing former England boss Allardyce the following day, comes after back-to-back defeats and moves them two points clear of the relegation zone.
Watford climbed to 10th before seven more Premier League matches on Boxing Day.
Allardyce said he hoped to "bring some joy, particularly over Christmas and New Year" when he started his first management role since his ill-fated 67 days as England boss, but another soft goal prevented a perfect start at the club.
Palace have failed to keep a clean sheet in 22 of their last 23 Premier League games and have conceded 33 goals this season with only Swansea and Hull - in 19th and 20th respectively - conceding more.
Allardyce's teams are renowned for the defending of set pieces and the 62-year-old will no doubt be disappointed with Watford's equaliser.
Referee Mark Clattenburg gave a foul against Palace defender Damien Delaney for pulling back Prodl at a corner before Deeney fired home from the spot.
Palace chairman Steve Parish said the club's "expansive style of football hasn't worked" and they need to "wind the dial back the other way" following Allardyce's appointment.
The new manager named an attacking starting line-up, however, recalling winger Andros Townsend who had been left out of the starting XI for the Eagles' previous two games.
It was the England winger who set up Cabaye for Palace's goal with his first assist for the club since joining from Newcastle in the summer.
The Eagles dominated the first half - helped by the fact defender Daryl Janmaat and midfielder Valon Behrami both went off injured for Watford within the opening 15 minutes - and would have fully deserved a two-goal lead had Benteke converted from the spot.
The Belgian used his usual stuttered run-up for the spot-kick, which lacked power and was comfortably saved by Gomes.
Watford improved after the break - producing eight of their nine shots in the second half - and punished the Belgian for his miss.
By contrast, Deeney blasted his penalty down the middle to beat Wayne Hennessey.
"When you're not having the best of moments in front of goal, just smash it down the middle," said the 28-year-old, who had not scored since the beginning of October.
Palace had a late appeal for another penalty turned down by Clattenburg when Miguel Britos tackled Wilfried Zaha but the referee chose to book the winger for simulation.
When asked if he thought the decision to award Palace a penalty was soft, Allardyce said: "Not really, you grab players in the box knowing some referees give it and some don't.
"The Watford player himself did a great job of rolling over and Clattenburg saw it but I am still bemused he didn't give the one for Zaha," he added.
"There was contact there and he gets booked for it, while Gomes does a hatchet job and doesn't even get booked."
Watford manager Walter Mazzarri, speaking to BBC Sport: "I'm happy with the point. But today is the first game I don't like since I am here.
"Everything is happening to us because we had two injured players after 15 minutes and that can change any team, but still today the players could have done much better. It was not only one or two but many of them. So I am not happy with this.
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"I am happy with the point and that Deeney scored his 100th goal - that had been a heavy weight he was carrying. Now this is over."
Crystal Palace manager Sam Allardyce, speaking to BBC Sport: "The missed penalty, that was a big moment in the game, then we gave a soft penalty away when we had hardly looked in danger at all. We just didn't finish the opposition off.
"You are a bit apprehensive about what you have got, but from I have seen we have some real talent. I just have to build the resilience a bit more and we will be OK."
Media playback is not supported on this device
Allardyce's second game in charge of Crystal Palace is a trip to Emirates Stadium to play Arsenal on New Year's Day (kick-off 16:00 GMT). Watford host Tottenham on the same day (kick-off 13:30 GMT).
Match ends, Watford 1, Crystal Palace 1.
Second Half ends, Watford 1, Crystal Palace 1.
Foul by Jerome Sinclair (Watford).
Yohan Cabaye (Crystal Palace) wins a free kick in the defensive half.
Miguel Britos (Watford) is shown the yellow card for a bad foul.
Foul by Miguel Britos (Watford).
Christian Benteke (Crystal Palace) wins a free kick in the attacking half.
Attempt saved. Adlène Guédioura (Watford) left footed shot from outside the box is saved in the bottom left corner.
Etienne Capoue (Watford) wins a free kick in the attacking half.
Foul by Jason Puncheon (Crystal Palace).
Wilfried Zaha (Crystal Palace) is shown the yellow card.
Wilfried Zaha (Crystal Palace) has gone down, but that's a dive.
Miguel Britos (Watford) wins a free kick in the defensive half.
Foul by Wilfried Zaha (Crystal Palace).
Substitution, Watford. Jerome Sinclair replaces Juan Zuñiga.
Delay over. They are ready to continue.
Delay in match Troy Deeney (Watford) because of an injury.
Attempt saved. Odion Ighalo (Watford) header from the centre of the box is saved in the centre of the goal. Assisted by Adlène Guédioura with a cross.
Offside, Crystal Palace. Damien Delaney tries a through ball, but Christian Benteke is caught offside.
Substitution, Crystal Palace. Fraizer Campbell replaces Mathieu Flamini.
Foul by José Holebas (Watford).
Wilfried Zaha (Crystal Palace) wins a free kick on the right wing.
Foul by Adlène Guédioura (Watford).
Jordon Mutch (Crystal Palace) wins a free kick in the attacking half.
Foul by Adlène Guédioura (Watford).
Wilfried Zaha (Crystal Palace) wins a free kick in the defensive half.
Corner,  Watford. Conceded by Damien Delaney.
Foul by Miguel Britos (Watford).
Martin Kelly (Crystal Palace) wins a free kick in the defensive half.
Corner,  Watford. Conceded by Yohan Cabaye.
Substitution, Crystal Palace. Jordon Mutch replaces Andros Townsend.
Attempt missed. Scott Dann (Crystal Palace) header from the centre of the box is too high. Assisted by Jason Puncheon with a cross following a set piece situation.
Foul by Sebastian Prödl (Watford).
Wilfried Zaha (Crystal Palace) wins a free kick in the attacking half.
Goal!  Watford 1, Crystal Palace 1. Troy Deeney (Watford) converts the penalty with a right footed shot to the centre of the goal.
Damien Delaney (Crystal Palace) is shown the yellow card for a bad foul.
Penalty Watford. Sebastian Prödl draws a foul in the penalty area.
Penalty conceded by Damien Delaney (Crystal Palace) after a foul in the penalty area.
Corner,  Watford. Conceded by Andros Townsend.
Attempt missed. Juan Zuñiga (Watford) right footed shot from outside the box is too high. Assisted by Troy Deeney with a headed pass following a set piece situation.


Dozens of police commandos have been killed in heavy fighting with Islamist rebels in the southern Philippines province of Maguindanao, say officials.

Several rebels were also reportedly killed as police entered a village held by the Moro Islamic Liberation Front (Milf) early on Sunday.
Reports say two key terror suspects were the targets of the operation.
It is the worst fighting since the government and Milf signed a peace deal last year to end decades of fighting.
There was conflicting information about Sunday's fighting, but reports from the Philippines suggest police commandos launched a surprise raid on a village near the town of Mamasapano, in the Maguindanao province of Mindanao island.
They were reportedly seeking to arrest members of the Bangsamoro Islamic Freedom Fighters (Biff), a Milf splinter group which opposes the ceasefire.
But the mayor of the town, Tahirudin Benzar Ampatuan, said police had not warned the Milf of the raid, as they should have under the peace deal, so its members fought back.
The gunfire reportedly went on for several hours.
The number of casualties remains unclear. Local and international news reports citing various officials put the number of commandos killed between 40 and 50.
Milf leaders confirmed the violence but the number of rebels killed and their affiliation was not clear. The violence ended when ceasefire monitors intervened, said local officials.
The military was not involved, but peacekeeping reinforcements have since been sent to the region.
National police chief Leonardo Espina said in a statement that information was "sketchy" but that there was "an ongoing operation in the area against a high-value target believed to be behind the recent spate of bombings in Central Mindanao".
Various reports said police were pursuing Zulkifli bin Hir, known as Marwan - a leading figure of Islamist group Jemaah Islamiyah (JI) - as well as suspected JI bomb-making expert Basit Usman, who is linked to the Biff.
JI has links to al-Qaeda and wants an Islamic state across South East Asia. It has a long track record of bomb attacks in Indonesia and elsewhere in the region.
Marwan, who is on the FBI's most-wanted list, is believed to have been in hiding in the southern Philippines for over a decade.
Both men have been incorrectly reported killed several times. The US has offered rewards for their capture.
Last year's peace deal promised the separatists more autonomy in return for an end to their insurgency. It established peacekeeping procedures but correspondents say they appear to have failed.
The movement's leading peace negotiator, Mohagher Iqbal, told AFP the violence was "a big problem" but that the peace deal still held.


Women aged in their 20s and 30s are risking poverty in retirement by cutting contributions as they pay for childcare, a think tank says.

The Fawcett Society, which campaigns for equality, said many young women were relying on their partner for financial security in retirement.
It said many women in this age group were taking on the full cost of childcare.
The government said free childcare was being doubled.
The Fawcett Society said that student debt, childcare costs, and a break from work were preventing women from saving for later life.
Sam Smethers, chief executive, said: "The gender pay gap becomes a pensions gap in retirement. In particular, women are taking a big hit on their pensions when they have children, but are not aware of the impact this will have on them in the long-term.
"Women are putting everyone else's needs before their own, especially when it comes to who pays for childcare. Their baby becomes her childcare bill."
A Department for Work and Pensions spokesman said: "We want all women to have a financially secure retirement, which is why we introduced wide ranging reforms to make pension saving easier and clearer, including through the introduction of the new state pension and automatic enrolment.
"We are also committed to supporting mothers by making childcare more affordable and more accessible, and we are doubling free childcare for nearly 400,000 working parents of three and four-year-olds from 15 to 30 hours."
The Pensions Policy Institute recently warned that the new state pension, introduced this month, will leave more than 11 million workers now aged their 20s and 30s worse off than they would have been under the previous system.
A BBC News investigation in 2010 revealed how pensions had fallen down the priority list for many young women.


A thriller in which a hit-man is forced to undergo gender reassignment surgery has been defended by its stars at its Toronto Film Festival premiere.

In (re)Assignment, Michelle Rodriguez plays a male assassin who awakes to find himself transformed into a woman.
The film has been criticised by some in the LGBT (lesbian, gay, bisexual and transgender) community for using surgery as a sensational plot device.
But actress Sigourney Weaver said no-one was "demeaned or denigrated".
The Alien star plays the deranged surgeon who performs the operation. "It's not a Disney movie - it is noir," she said.
At the film's world premiere on Wednesday, its director Walter Hill said: "It's a crime story, it's a noir vision, it's comic book in a way.
"Quite a few women have said to me that after seeing the movie, they feel empowered by it."
Rodriguez, meanwhile, said her own bisexuality inured it from criticism, explaining: "You can't really argue with me because I'm you.
"I'd never do a movie with the intention of offending anybody in the LGBT community because I'm a part of it."
The festival's official website calls (re)Assignment a "jaw-droppingly audacious revenge thriller" that "confronts the gender binary on which so much genre cinema is based."
Some reviewers have taken a tougher line, though, with one calling it "a strong contender for 2016's worst movie".
It is, continued The Guardian's critic Benjamin Lee, "a film made with such staggering idiocy that it deserves to be studied by future generations".
The film got equally short shrift from Variety's Dennis Harvey, who dismissed it as "crude", "drab-looking" and "unintentionally funny".
But it got more love from the Hollywood Reporter, whose critic Todd McCarthy found it "deliciously transgressive" and "an instant cult item".
It is not known yet whether (re)Assignment will receive a UK release.
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An inquiry into the impact of Brexit on devolution in Wales, Scotland and Northern Ireland is being launched by a Westminster committee.

The Lords' EU Committee will hear from academics, business leaders and politicians in Cardiff on 7 February.
The short inquiry will consider how UK ministers should reflect the devolved nations' interests in Brexit talks.
It will also discuss which powers should be devolved when they are transferred from Brussels.
The UK as a whole voted for Brexit in June's referendum, as did England and Wales.
However, poll results in Scotland and Northern Ireland showed a majority there wanted to remain part of the EU.
On Friday, committee chairman Lord Boswell said this "presents challenges for the forthcoming Brexit negotiations".
"We want to get to the bottom of the effect of Brexit on the devolution settlement, and how the different views across England, Scotland, Wales and Northern Ireland can all be fairly represented in the forthcoming negotiations," he said.
"We will explore issues including which powers returning to the UK from Brussels should be devolved, and the resources that the devolved institutions will need to take on these responsibilities."
The Conservative leader in Wales, Andrew RT Davies, has warned that Welsh ministers lack the capacity to make Wales-only agriculture policies post-Brexit, despite farming being devolved.


League Two side Blackpool have signed Leicester City midfielder Michael Cain on a season-long loan deal.

The 21-year-old moved to the Premier League champions in 2011 from Luton and has played for their development side.
He has previously spent time on loan at Mansfield and the 2014-15 season in League One with Walsall.
"He plays forward and he wants to create something. I just felt that we needed that in the squad," boss Gary Bowyer told the club website.
Find all the latest football transfers on our dedicated page.


A Dundee mother-of-13 has said she "can't wait" to become a grandmother for the first time in the summer.

Emma Hann and husband Roy's 13 children are aged between two and 25, with eight of them still staying at the family home.
Their 22-year-old daughter Polly and son-in-law Michael Watt are expecting their first child in August.
The family will run the new Race For Life Family 5K after Cancer Research UK asked them to launch the event.
Mrs Hann, 47, told BBC Scotland: "We're really excited, really delighted.
"When Polly went to see the midwives, they all knew who her mum was.
"It's a little bit sad because Polly and Michael have just moved to Dunfermline, they were just living across the road from us.
"But it's been amazing watching her little bump starting to grow and knowing that's my little grandbaby."
The family gets through 50 pints of milk, 21 loaves of bread and five large boxes of cereal every week.
Until the expectant couple's recent move to Fife, 10 of the Hann children stayed with their parents in their six-bedroom Dundee home.
Mrs Hann said: "Two of her sisters, Alice and Sophia, are staying in her (Polly's) little house just across the road.
"We still see a lot of everybody, but it is nice having a little bit more bedroom space."
The Race for Life Family 5K runs will take place in June alongside the traditional women-only events at 10 locations across Scotland.
Mrs Hann said: "Some of my older girls have been involved in Race for Life on a few of the years, so to be asked to be involved with it is really exciting.
"We're all planning to be there and all excited about it."


Barclays chief executive Bob Diamond has resigned a week after the bank was fined a record amount for trying to manipulate inter-bank lending rates.

BBC business editor Robert Peston said he was encouraged to go by the heads of the Bank of England and the FSA.
Mr Diamond said he was stepping down because the external pressure on the bank risked "damaging the franchise".
Chief operating officer Jerry del Missier has also resigned, the third top executive in two days to do so.
Barclays chairman Marcus Agius, who had announced his own resignation on Monday, will now take over the running of Barclays until a new chief executive is appointed.
BBC business editor Robert Peston said the heads of the City's two main regulators had been unable to force Mr Diamond out "because the recent FSA investigation into how Barclays attempted to rig the important Libor interest rates did not find him personally culpable".
By Robert PestonBusiness editor
FSA boss slams 'greed' at banks
"However, as a regulated institution, it was impossible for Barclays' board to ignore the revealed wishes of the two most powerful regulators in the City."
Earlier, Lord Turner, the chairman of the Financial Services Authority, described the outrage that has built up over the bank's actions.
"The cynical greed of traders asking their colleagues to falsify their Libor submissions so that they could make bigger profits - has justifiably shocked and angered people, in particular when we are facing hard economic times provoked by the financial crisis," he told the Financial Services Authority's annual meeting.
•
            27 June: Barclays fined £290m by US and UK regulators for attempting to manipulate Libor rates
•
            28 June: Barclays shares plunge 15%
•
            29 June: Bank of England governor calls for change in banking culture
•
            1 July: It emerges that RBS has sacked four traders over Libor and there are calls for changes in the law to cover Libor-rigging
•
            2 July: Barclays chairman Marcus Agius resigns and the government launches two inquiries into Libor and banking standards
•
            3 July: Barclays chief executive Bob Diamond resigns
Timeline: Libor-fixing scandal
Criminal charges: The problems
Mr Diamond will still appear before MPs on the Treasury Committee on Wednesday to answer questions about the Libor affair.
"I look forward to fulfilling my obligation to contribute to the Treasury Committee's enquiries related to the settlements that Barclays announced last week without my leadership in question,"
          Mr Diamond said in a statement.
He is expected to be questioned about a conversation he had with the deputy governor of the Bank of England, Paul Tucker, about Barclays' Libor submissions at the height of the credit crunch in 2008.
Barclays' managers came to believe, after the conversation between Mr Diamond and Mr Tucker, that the Bank of England had sanctioned them to lie about what they were paying to borrow when providing data to the committees that set the Libor rate.
Chancellor George Osborne welcomed Mr Diamond's departure and said he hoped it was the "first step towards a new culture of responsibility" in banking.
"It is the right decision for the country," Mr Osborne said, saying the UK needed a strong Barclays concentrating on lending and contributing to economic recovery.
Labour leader Ed Miliband said it was "necessary and right" that Bob Diamond stepped down.
"But this is about much more than one individual, it's about the culture and practices of the banking industry," he said.
"That's why we need a full, judge-led, independent inquiry, to get to the bottom of those practices and make recommendations for change in the future. We've had missed opportunities before, we've got to seize this moment."
Labour is critical of the government's decision to call a parliamentary inquiry, chaired by the head of the Treasury Committee, Andrew Tyrie MP, rather than a full Leveson-style inquiry, independent of politicians.
Last week, regulators in the US and UK fined Barclays £290m ($450m) for attempting to rig Libor and Euribor, the interest rates at which banks lend to each other, which underpin trillions of pounds worth of financial transactions.
By Nick RobinsonPolitical editor
Q&A: Row over Barclays inquiry
Labour 'must see sense on banks'
Staff did this over a number of years, trying to raise them for profit and then, during the financial crisis, lowering them to hide the level to which Barclays was under financial stress.
Mr Diamond is one of the UK's highest paid chief executives, earning £20m last year, and was described as "the unacceptable face" of banking by the then business secretary Lord Mandelson in 2010.
The details of any severance package are not yet known, but former City minister Lord Myners suggests it could add up to £20m-£30m.
"I think his resignation letter is drafted with an eye to that [pay-off], because he admits no guilt on his part at all," the Labour peer told BBC News.
"The shareholders of Barclays will be expecting the board to ensure that not a penny more is paid to Bob Diamond than that to which he is legally entitled," he said.
US-born Mr Diamond was head of Barclays Capital, its investment bank division, when its staff were trying to manipulate the key inter-bank rates.
"He maintains that he didn't know what was going on," says Robert Peston.
Investigations are continuing in the UK and the US into other banks over Libor fixing, including criminal investigations by the Department of Justice.  The Serious Fraud Office in the UK is looking into possible criminal prosecutions.


Colchester have signed defender Lewis Kinsella on a two-year deal following his release by Aston Villa.

Kinsella left Villa in May, having failed to make a first-team appearance for the Championship club.
The 21-year-old joined Kidderminster Harriers on loan in February, playing in 13 games.
He suffered relegation twice in one day last season, with Harriers going down on 16 April as the end of Villa's Premier League stay was confirmed.
Find all the latest football transfers on our dedicated page.


Tunisia's interim government has said elections, due to be held in July, will be postponed for three months.

The Tunisian electoral commission had asked for the delay, saying it needed more time to prepare a credible vote.
The country's interim Prime Minister Beji Caid Essebsi said the vote will now take place on 23 October 2011.
Critics say that elections should go ahead soon to bring an end to the instability following the overthrow of President Zine al-Abidine Ben Ali.
But many recently formed political parties say they need more time to prepare.
Last month, the electoral commission sought a delay, saying that it needed more time to organise the vote, including putting three million Tunisians into the electoral database and ensuring hundreds of thousands of others get valid identity cards.
Reputation
"There are parties who did not agree, even the government did not agree, but our mission is to hold free and transparent elections," said Mr Essebsi, adding that Tunisia and its revolution "have a reputation that we must protect".
The date was the result of several weeks of negotiations between political groups to establish a date for the first election since the popular uprising which brought about the fall of Mr Ben Ali, forced to cede power on 14 January after 23 years in power.
Mr Essebsi said that Tunisia's fledgling experiment with democracy - which triggered a series of pro-democracy revolts across the Middle East - was being closely observed.
"The world is watching us. Tunisia today has an extraordinary image because its revolution happened peacefully, without weapons," he said, adding: "The wind of freedom has blown through other countries... but we will be the only ones to succeed in putting into place a democratic government."
October's vote is for a constituent assembly to write a new constitution that would pave the way for legislative and presidential elections.
The new assembly will decide whether the country gets a presidential or parliamentary system, and whether a separation of religion and state becomes law.
Under Mr Ben Ali's 23-year rule, a single party - now officially dissolved - controlled the country and opposition parties in parliament were largely symbolic.
Since his overthrow a total of some 81 new parties have been officially registered.


Part of the garden at Queen Victoria's private family home on the Isle of Wight is being opened to the public for the first time.

The Osborne House lower terrace, where the Queen wrote and painted, has been restored by English Heritage at a cost of Â£600,000.
The organisation said falling masonry and broken steps had made the terrace too dangerous to open previously.
It said the terrace was the last major part of the property to be repaired.
Part of the work included restoring the Italian-inspired yellow colour of the walls to match the rest of the property.
Also restored are the centrepiece Andromeda fountain and the ornate Shell Alcove, decorated with thousands of sea-shells from the beach below.
Samantha Stones, English Heritage's Properties Curator at Osborne, said: "Queen Victoria loved to be outside in the fresh sea air and the terrace was a place of peace."


A conservation charity has helped a woman identify a "lost" World War Two airfield where her father flew.

Elizabeth Halls, from Herefordshire, is making a tour of 60 aerodromes where her father, Flight Lieutenant Bryan Wild, landed Defiant planes.
Mr Wild died in 2012 and Mrs Halls used his memoirs to identify the sites, one of which, named "Uppingdon", she had struggled to find.
But the National Trust believes the site was at Uckington in Shropshire.
Mrs Halls, from Stansbatch near Leominster, enlisted the help of an aviation historian to edit her father's memoirs, which have now been published.
She has embarked on a sponsored six-month tour of the airfields in a 1935 Singer Le Mans sports car, similar to one her father owned during the war, to raise money for the RAF Benevolent Fund.
While in Shropshire, she will also be visiting an old RAF airfield at High Ercall, where her father was stationed for two weeks in 1942.
"Dad talks about Uppingdon Airfield in his notes, but although there is a village of that name, I can't find any mention of an airfield," she said.
"I do know that it was next to Attingham Park, which is where the US base Atcham was, so it may be that my father is referring to Atcham, but I would love to find out for sure."
Bob Thurston, countryside parks and gardens manager at Attingham Park said he believed Mrs Halls was "almost certainly" referring to Uckington, at the south east edge of the Atcham airfield.
"One of the runways was on Uckington farm fields," he said.
"To confuse matters, there are also the villages of Uppington and Uffington nearby, though they had no airfield or airfield buildings associated with them."


Uber has agreed to pay $20,000 (Â£13,700) and to strengthen its privacy policies to settle an investigation by New York's attorney general.

It follows allegations that the app-based taxi company was able to monitor the whereabouts of passengers through its geolocation technology.
It also failed to report a major data breach to authorities in a timely way.
Uber said it had adopted all of the safety measures requested prior to reaching the settlement.
The investigation followed a BuzzFeed News story in 2014 that alleged one of its reporter's rides had been tracked without her permission.
This was allegedly done through an internal company tool called "God View", which shows the location of Uber vehicles and customers who have requested a car and which was reportedly widely available to corporate employees.
The attorney general also said Uber had taken five months to inform its drivers about a breach involving their personal data.
The breach, which affected 50,000 drivers, occurred in May 2014 and was discovered by Uber in September 2014.
But the firm admitted it did not tell its drivers or the public until February 2015.
Uber said it had already removed all personally identifiable information of riders from its location system and undergone a privacy audit.
According to the settlement, it must also encrypt GPS-based location information and authenticate any employee accessing this data for business purposes.
An Uber spokeswoman told the Wall Street Journal the firm was "pleased to have reached an agreement".
"We are deeply committed to protecting the privacy and personal data of riders and drivers," she said.