Foreign minister Jean-Yves Le Drian says two French citizens have been missing since the attack. Mr Le Drian confirmed that one French citizen died and eight were injured, four of them seriously.

London Mayor Sadiq Khan has spoken at the vigil.

He said the city "stands in defiance against this cowardly attack".

"I want to send a clear message to the sick and evil extremists who commit these hideous crimes. We will defeat you. You will not win," he said.

He was joined on stage by Home Secretary Amber Rudd (L) and Shadow Home Secretary Diane Abbott.

Image source, AFP

Image source, Getty Images

Dominic Casciani
Home Affairs Correspondent

Khuram Butt, one of the three London attackers, became known to the police and MI5 in the summer of 2015 - but according to Scotland Yard there was no intelligence that he was then plotting.

An investigation was opened into his behaviour after concerns reached counter-terrorism officers. After that investigation was opened, there was a call from a member of the public about his radicalisation - but there was no evidence he was planning an attack.

The BBC has been told by two people in Barking that they raised concerns about Butt.

One man called the anti-terrorism hotline in 2015 while a woman went to the local police station because she was scared Butt was trying to radicalise her children.

Security planners made him a lower priority than other targets because of a lack of information that he was involved in attack-planning.

Critically, Butt then attracted less investigatory resources. The question is whether there was, at the time, anything in his covert communications that might have led to a different decision, had it been known.

Hundreds have descended on Potters Field Park to remember the victims of Saturday's attack.

BBC London's Matthew West, who is at the vigil, sent us this:

Image source, afp

Image source, Reuters

Image source, AFP

Image source, Getty Images

Melissa McMullan says her brother James is thought to be one of the London terror attack victims.

Image source, Reuters

Work to inform the next of kin of the seven victims of Saturday's attack is ongoing, the Metropolitan Police says.

"This is taking time because we believe some of the victims are from abroad," it said in a statement.

A Canadian woman is the first victim to be identified. She is Christine Archibald, 30, a former homeless shelter worker, who died in her fiancé's arms after being struck by the speeding van on London Bridge, her family says.

French Foreign Minister Jean-Yves Le Drian has said that a Frenchman was also killed and two French citizens were missing.

The Met says that 36 people are still in London hospitals, with 18 of them in a critical condition.

Khuram Shazad Butt was known to the police and MI5, The Met's Counter Terrorism Command has said.

However, there was no intelligence to suggest this attack was being planned and the investigation had been prioritised accordingly, they said in a statement.

The other named man, Rachid Redouane, was not known.

Police said work was ongoing to understand more about them, their connections and whether they were assisted or supported by anyone else.

Seven women and five men were arrested during raids in London, the Metropolitan Police said.

Police made the arrests at two addresses in Barking.

Two people - one man and one woman - have since been released without charge.

Those arrested range in age from 19 to 60.

In total, six properties have been searched.

Image source, Met Police

Khuram Shazad Butt, 27, was a British citizen who was born in Pakistan, police say.

Rachid Redouane, 30, had claimed to be Moroccan and Libyan.

He also used the name Rachid Elkhdar, with a different date of birth.

Inquiries are ongoing to confirm the identity of their accomplice.

Detectives would like to hear from anyone who has any information about these men that may assist them with the investigation. They are particularly keen to hear about places they may have frequented and their movements in the days and hours before the attack.

The Met have named Rachid Redouane, from Barking, east London as one of the three attackers.

Formal identification has yet to take place.

Large crowds have now gathered for the vigil in remembrance of those killed in Saturday's attack.

Mayor of London Sadiq Khan is due to speak.

One of the three men who launched the attack was Khuram Butt, 27, the BBC understands.

He lived in Barking, east london. His home was raided by police on Sunday.

Image source, Reuters

Barriers are being built on a number of bridges in London following Saturday's attack. They have been described by the Metropolitan Police as "increased security measures".

The Met has reviewed all 33 of the capital's bridges and, as a result, it quickly began installing protective barriers.

Westminster Bridge, where a man ploughed a car into pedestrians in March, was the the first to have them installed, the Met said.

Barriers will also be installed on Waterloo Bridge and Lambeth Bridge to maintain security at these venues, it added.

Is it the way to go to prevent other attacks?

Read more here

BBC London reporter Alpa Patel is on Facebook live at Potters Fields Park.

Image source, Reuters

Newspaper El Pais, external has more on the Spanish man who is still missing after Saturday's attack. He is 39-year-old Ignacio Echeverría, from Madrid, who works as a banker at HSBC in London.

Relatives said he was returning from a park with friends when they saw a man stabbing a woman at Borough Market. Mr Echeverría then stopped to rescue her from the aggressor, they added.

The last time he was seen he was lying on a sidewalk, the newspaper said.

The Spanish consulate in London is helping the family in their search efforts and any information can be given at 07938633876, 07582314487 or 0771276415.

Meanwhile, Spain's interior minister says that a Spanish man who is being treated in hospital is in a not-serious condition, without giving further details.

People have begun to arrive at Potters Fields Park ahead of the vigil at 1800 BST.

Pupils from Eden Girls School in Walthamstow arrived with flowers.

Badriyah, 14, said: "We wanted to pay our respects for the victims of the attack."

Hanyah, 14, added: "No-one would wish this on anybody and we just wanted to make that clear."

School principal Shah Ina Ahmad said: "We thought it was very important to make the point to the people that do this, that they do not represent other Muslims and to show we do not agree with the people that have done this."

More than 130 Imams across the country have refused to perform the Islamic funeral prayer for the London terror attackers.

The prayer is usually performed for every Muslim - regardless of their actions. The list of Imams has been published on the Muslim Council of Britain website, external.

Image source, EPA

UKIP leader, Paul Nuttall, has said that PM Theresa May "got it wrong" over police cuts.

"I also think she's got it wrong over border guard cuts as well and indeed (with) cuts to the prison service," he added.

He said that, as well as reversing cuts to the police, there was the need to "get the Muslim community on side".

"I think we need to get them signed up to the Prevent programme, I think the fact that only one out of eight referrals that go to Prevent come from within the Muslim community itself is indeed worrying".

However, he suggested that Labour leader Jeremy Corbyn's criticism of Mrs May did not have "legitimacy".

Mr Corbyn, he said, had called Hamas and Hezbolloh friends and added: "To attack Theresa May on the issue of terrorism, I think really is a weak point for Jeremy Corbyn."

The Independent Police Complaints Commission has started its investigation into the events of Saturday night.

In a statement IPCC Deputy chairwoman Sarah Green said: "We can confirm that 46 shots in total were fired by eight police officers - three officers from City of London Police and five from the Metropolitan Police Service.

"We are examining CCTV footage from within Borough Market which we believe shows the majority of the incident relevant to our investigation."

It said it has a duty to investigate fatal police shootings and was important to stress that no individual police officers are under investigation.

"I recognise that this was a fast-moving and dangerous situation which the police had to respond to extremely quickly. This investigation is being given the highest priority and we aim to complete it at the earliest opportunity," Sarah Green said.

The sister of 32-year-old James McMullan, from Hackney, east London, has paid tribute to her brother.

His bank card was found on a body at the scene.

Here's a tweet from our special correspondent Lucy Manning: