Twelve people have been arrested after the London terror attack which left seven people dead and 48 injured.
The arrests in Barking, east London, followed a raid at a flat belonging to one of the three attackers.
A van hit pedestrians on London Bridge at 9.58pm local time on Saturday. Three men then got out and stabbed people in nearby Borough Market.
Seven people were killed, while 48 were injured.
Police said one man, of the five men and seven women detained under terrorism legislation, had been released.
One of the dead, a Canadian woman, 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 fiance.
New Zealand's Ministry of Foreign Affairs and Trade said assistance was being provided to the family of Christchurch man Oliver Dowling who was stabbed multiple times during yesterday's attack.
The BBC reported Mr Dowling had surgery for his wounds, which missed his vital organs.
The Ministry said the High Commission in London was in touch with Mr Dowling's family and was providing consular assistance.
The three attackers were shot dead within eight minutes of the first 999 call being received, by eight officers who fired 50 bullets.
Islamic State has reportedly claimed responsibility for the terror attack in London yesterday that left seven people dead.
Police said they would make public the names of the three men who were shot dead by officers as soon as possible.
A member of the public was accidentally shot and remains in hospital in a non-critical condition, Assistant Commissioner Mark Rowley said.
"The situation these officers were confronted with was critical, a matter of life and death - three armed men wearing what appeared to be suicide belts," he said.
"They had already attacked and killed members of the public and had to be stopped immediately."
The suspected suicide vests were later found to be fake.
Mr Rowley, the chief of the UK's Counter Terrorism Police, said they were increasingly confident the attack was carried out by three individuals, but it needed to be establishes whether others were involved in planning.
He said security plans at forthcoming events were being reviewed, and cordons at London Bridge and Borough Market would remain in place for some time.
Thirty-six people were in hospital with a "range of injuries", he said, and 21 were in a critical condition.
Elizabeth O'Neill - mother of 23-year-old Daniel O'Neill, who was stabbed - said her son had a seven-inch wound from the knife attack.
"He had just stepped outside the bar for a second and a man ran up to him and said 'this is for my family, this is for Islam' and put a knife in him," Ms O'Neill said.
"I'm still in shock. I can't quite believe it's happened."
Controlled explosions were carried out at the flat in Barking during the raids on Sunday morning.
According to neighbours, the dead attacker lived there for about three years and was married with two children.
Most political parties have suspended national general election campaigning, but the prime minister said full campaigning would resume on Monday.
The general election will go ahead as planned on Thursday.
Condemning the attack, Theresa May said it was "time to say enough is enough".
Four police officers who tried to stop the attack were among those injured, two of them seriously.
One of them was an off-duty officer and amateur rugby player who tackled one of the terrorists, suffering stab wounds.
Another, a British Transport Police officer who joined the force less than two years ago, took on the attackers armed with only his baton.
Metropolitan Police Commissioner Cressida Dick praised their "extraordinary bravery".
Among the main developments:
- Prime Minister Theresa May has made a private visit to King's College Hospital in south London to visit some of the injured
- There will be a minute's silence on Tuesday at 11:00 BST in remembrance of those who lost their lives and all others affected by the attacks
- A Canadian national was among those killed, the country's Prime Minister Justin Trudeau has said
- Two Australian citizens "have been directly impacted" says the country's Prime Minister Malcolm Turnbull
- Four French citizens have been injured, one seriously, according to foreign minister Jean-Yves Le Drian
- The Met Police has set up a casualty bureau on 0800 096 1233 and 020 7158 0197 for people concerned about friends or relatives
It is the third terror attack in the UK in three months, following the car and knife attack in Westminster in March, in which five people were killed, and the Manchester bombing less than two weeks ago, in which 22 people were killed.
Greater Manchester Police said they had now arrested an 18th person, a 20-year-old man, in relation to the Manchester bombing.
Twelve men aged between 18 and 44 are now in custody on suspicion of terrorism offences in connection with that attack, which hit a concert by Ariana Grande at the Manchester Arena.
Six people have been released without charge.