The identities of the three attackers have not yet been revealed but it's thought one of them was living in Barking, east London, and had recently hired the van used in the attack.
British Prime Minister Theresa May blamed "evil" Islamist ideology Sunday for an attack by knife-wielding men who mowed down and stabbed revellers in London, killing seven, as police said they had arrested 12 suspects. In addition, three attackers were shot dead by police.
This is the third attack in Britain in as many months.
The attack in central London came just weeks after a suicide bombing at a concert in Manchester left 22 dead, and it recalled an attack in March when a man drove a auto into pedestrians near the seat of Parliament, killing five. Grande and other stars are scheduled to perform a benefit concert for victims under tight security in Manchester Sunday night.
"We will never be cowed by terrorism", he said, calling the attackers "barbaric cowards".
She said he had been unable to find her, and the police had yelled for everyone to stay down. May added that the extremist ideology "is a perversion of Islam and a perversion of the truth".
The sequence of attacks has at times overshadowed the election. In March, in an attack similar to Saturday's, a man killed five people after driving into pedestrians on Westminster Bridge in central London.
Then came the May 22 Manchester concert bombing. After that attack, Britain's official terrorism threat level was raised from "severe" to "critical", meaning an attack may be imminent.
May called on worldwide communications companies to do more to block cyberspace to extremist groups who use it for recruitment and for encrypted information about plots.
"I can't imagine Theresa May tweeting like this to the mayor of Orlando or San Bernadino", said Heye.
Major parties suspended national campaigning Sunday out of respect for the victims, although the right-wing UK Independence Party said it would keep campaigning to show the extremists they couldn't sidetrack democracy. It is unclear how the unprecedented violence in the run-up to the election will impact voter sentiment.
Three Australians are now believed to have been caught up in the London Bridge terrorism attack, Julie Bishop has said.
May said on Sunday that a new approach to tackling extremism is required, including changes that would deny terrorists and extremist sympathizers digital tools used to communicate and plan attacks.
Ontario Premier Kathleen Wynne said in a tweet Saturday that Canadian hearts were heavy with the news of the violence in London.
Thirdly, she said, more needed to be done to identify and stamp out extremism across British society.
As dawn broke over the capital, a large area on the south bank of the River Thames remained cordoned off. Police told people to avoid the area, leaving tourists and revelers struggling to get home.
Both London Bridge rail and Tube stations will reopen on Monday from around 05:00 BST but the rail station will be exit only until at least 08:00 BST.
Dramatic footage and pictures have emerged on social media of gunfire ringing out as armed officers descended on Borough Market. Khan had earlier said Londoners would see an increased police presence on the streets of the city and people should not be alarmed by that.
Trump commented on the vehicle and knife attack that killed at least seven people in London.
Although police have "very good" resources and "extraordinarily highly-trained people" attacks are hard to predict, the police chief added.
He said that he helped a man and his partner, even taking the woman into his arms because she was too upset to walk properly. He said it took him 20 minutes to carry her across the bridge, stumbling all the way. "It was a rampage really", he said, adding that he heard a shout of: "This is for Allah".
Witnesses reported seeing injured people on the ground on the bridge. "And then I started picking up bottles, I threw a chair at them a stool, glasses - anything I could get my hands on".
"They kept coming to try to stab me. they were stabbing everyone".
"At what I know is an anxious time, my message to the public is to be vigilant and report anything of sus- picion to the police, but otherwise continue to live your lives as normal". I've been walking around for an hour and a half crying my eyes out.
Medics treated the wounded near the market as shocked people cried and shouted around them. Police officers yelled at people to run from the area.
"As the officers confronted the terrorists - and fired shots - a member of the public also suffered gunshot wounds".