The Canadian victim has been named by media outlets there as Christine Archibald.

Her family released a brief statement to Canadian broadcaster CTV, saying she had worked in a homeless shelter before moving to Europe to be with her fiancé.

The so-called Islamic State group has claimed responsibility for the attack on London last night.

Its news outlet Amaq, on the messaging app Telegram, said "a security unit of Islamic State fighters carried out the London attacks yesterday".

It was posted on IS channels on the messaging app at 22:26 BST.

The One Love concert, to raise money for the victims of last month's bombing, has been held in Manchester.

Ariana Grande led the list of celebrities who took to the stage, including Miley Cyrus, Take That, Katy Perry and Little Mix.

And there was a lot of praise on social media for the police officer spotted dancing with fans.

London's police force has issued an updated statement, saying the suspects will be identified as soon as possible.

"I would like to assure them and the public that this is directly assisting the progression of the investigation and confirm we will release the identities of the three men directly responsible for the attacks ... as soon as operationally possible," assistant commissioner Mark Rowley said.

He also thanked the news media for "restraint" in not speculating on the identity of suspects in a "fast-moving investigation".

He said officers "have been working tirelessly to process the crime scenes" and hopes that some areas around London Bridge will be re-opened on Monday morning.

London's Metropolitan Police have offered fresh details on the arrests made earlier today, and are still searching four other properties.

Officers made 11 of the 12 arrests at a single property, police said.

A 38-year-old woman was arrested at one address in Barking. At another, also in Barking, officers arrested:

• 28-year-old man
• 52-year-old man
• 55-year-old man
• 27-year-old man
• 55-year-old man, who has since been released without charge
• 49-year-old woman
• 60-year-old woman
• 19-year-old woman
• 27-year-old woman
• 24-year-old woman
• 53-year-old woman

Police said there were no arrests at two addresses in Newham, "although a number of people have been spoken to".

All of those arrested were detained under the Terrorism Act.

Image source, Getty Images

The former MP for Bermondsey & Old Southwark - which contains London Bridge's south side - says "the people who did this, they are not Muslim".

"If they were Muslim they would have been in Taraweeh, the evening prayer of Ramadan, they would not have been attacking innocent civilians," Labour's Neil Coyle, who is seeking re-election in the constituency, said.

"Let's not pretend they represent their faith, their religion, they don't, they were murdering and they would find any excuse to commit murder.

"This bit of London was really badly bombed week after week, month after month during the Second World War.

"The community spirit remained really resilient and we saw a glimpse of that in the short horrific attack last night."

Dominic Casciani
Home Affairs Correspondent

Three terrorism attacks on the UK in 75 days. Thirty-four people dead, many, many more injured. The five attackers all dead too.

By my calculations, this is the most sustained and bloody series of attacks outside of Northern Ireland since the IRA's 1974 winter bombing campaign (although there have been bigger individual attacks).

While the motive and aim has been the same, each appalling incident has differed significantly from the last.

These differences reveal the challenges faced by the security services in intercepting them before it is too late.

Read the rest of Dominic's analysis

Hospitals across central London are treating victims of the London Bridge terror attack, which killed seven people and injured 48.

There are currently 36 people being treated in five hospitals, with 21 in a critical condition, NHS England said.

Details are emerging about those caught up in the attack. None of those killed have been named so far.

Canada's Prime Minister Justin Trudeau said he was "heartbroken" that a Canadian national had been among those killed, but did not give further details.

Read more here

Theresa May should take responsibility if Britain has been too soft on extremists, the leader of Plaid Cymru has said.

Leanne Wood made the comments in a BBC TV debate this evening.

Referring to the prime minister's speech in the wake of the attack, where she said there had been "far too much tolerance of extremism in our country", Ms Wood pointed to the fact that Mrs May had been home secretary for six years prior to being prime minister.

The Question Time show will be broadcast on BBC One in Wales at 23:00 BST.

The Red Cross has launched a new UK Solidarity Fund to help victims of terrorism anywhere in Britain.

It is being launched in response to the attacks in London and Manchester, the Red Cross said - but is designed to have money available quickly when needed in future.

"Donations will help alleviate immediate suffering, and ensure that victims and their families do not face short-term financial difficulties," it said.

The organisation has also been running a "We Love Manchester" emergency fund, which has raised millions of pounds since the attack on 22 May.

Kathryn Stanczyszyn
BBC News Correspondent

Neighbours here have told me they're shocked and upset that one of the attackers may have been living in such close proximity.

Several have said they recognised one of the men in the images widely circulated today as living in the Elizabeth Fry flats - a fairly new building in a street full of modern housing, near to the centre of Barking.

Earlier, scaffolding and a tarpaulin were erected over the back garden of a ground floor flat as forensic work inside continue. Police officers at the front continue to man a cordon and check the identity of anyone trying to get in.

Scotland Yard say 12 arrests in all have been made in the Barking area, but it remains unclear how many were at this premises.

The acting US ambassador to the UK, Lew Lukens, has offered his support to London Mayor Sadiq Khan. US President Donald Trump earlier accused the mayor of downplaying the London terror attacks.

Image source, Reuters

Performers at the One Love Manchester concert have paid tribute to the courage of those affected by the terror attacks in Britain.

Before launching into his hit song "Happy", Pharrell Williams said: "I'm bowing because despite all the things that have happened here, I don't smell or feel or hear or see any fear.

"We feel love resilience and positivity."

Miley Cyrus, who duetted on the song, added: "For me the most important responsibility we have on this entire planet is to take care of one another. And look what we’re doing today and how amazing that is."

She dedicated her next song "to all the people that have been affected by this tragic event. [To] everyone getting back on their feet, I’m so proud of you."

Security Minister Ben Wallace has hit back at Labour leader Jeremy Corbyn's claim that Conservative cuts to police numbers threaten public safety.

He said: “This was a hastily arranged speech designed to help Jeremy Corbyn run from his record on counter-terrorism policy, but it failed."

Mr Wallace claims the Labour leader has "boasted about opposing every single counter-terror law" and had previously opposed the the use of "shoot-to-kill" by police.

He also claimed that Mr Corbyn had "given cover" to the IRA.