Britain's general election will go ahead despite the London terror attacks, Prime Minister Theresa May says.
Three suspects were shot dead by police after a van drove into pedestrians on London Bridge and attackers stabbed people on the street and in nearby bars, killing at least seven people and wounding about 50.
Several political parties including May's Conservatives and the main opposition Labour Party suspended campaigning on Sunday, but May said it would resume on Monday.
In a speech to the nation, Mrs May said the attack resulted from an evil ideology of "Islamist extremism" that preached hatred and sowed division and sectarianism.
"Violence can never be allowed to disrupt the democratic process, so those campaigns will resume in full...and the general election will go ahead as planned," she said in a televised statement in front of her Downing Street office.
She said Britain was experiencing a new trend as terrorism bred terrorism, and perpetrators were inspired to act.
There was far too much tolerance of extremism in the UK and that had to change, Mrs May said.
Police praise people's courage
The city's police chief says many people risked their own safety to help others and to treat those seriously injured during the attacks.
Commissioner Cressida Dick has paid tribute to them, along with the people who confronted the suspects.
"It's clear to me that the courage of those people during and following the attack was extraordinary and I pay tribute to all of them who came to the aid of those in need during this dreadful attack and I am sure helped to save lives."
Ms Dick said there would be increased patrols in many areas and some of these would include armed officers.
London Mayor Sadiq Khan said it was an "horrific terrorist attack" but urged citizens not to be cowed by the attack.
Words could not describe the anger and grief the people of the city would be feeling, he said.
Mark Rowley, Britain's top anti-terrorism officer, told reporters that police first began to get reports at 10.08pm that a vehicle had struck pedestrians on London Bridge.
"The vehicle continued to drive then from London Bridge to Borough Market, the suspects left the vehicle, attempting to stab a number of people.
"Armed response officers responded very quickly and bravely and confronted the three male suspects who were shot and killed in Borough Market."
The three attackers had been wearing what looked like explosive vests that were later found to have been fake.
A witness to the attack on London Bridge, Eric, said a white van going fast on the wrong side of the road veered to the right and hit a group of people trying to run away.
He said three men got out of the van with knives and went towards the group and started stabbing them.
He said the attackers were shouting "This is for Allah".
The attacks came within weeks of the May 22 suicide bombing in Manchester in northern England that killed 22 people at a pop concert by US singer Ariana Grande.
The Manchester bombing was the deadliest attack in Britain since July 2005, when four British Muslim suicide bombers killed 52 people in co-ordinated attacks on London's transport network.
The bridge incident is also reminiscent of an attack at Westminster Bridge which left five people dead including a police officer.
A third incident at Vauxhall was a stabbing but was unrelated to the terror attacks, police said.
Islamic State call
Islamic State, losing territory in Syria and Iraq to an advance backed by a US-led coalition, sent out a call on instant messaging service Telegram early on Saturday urging its followers to launch attacks with trucks, knives and guns against "Crusaders" during the Muslim holy month of Ramadan.
Similar attacks, in Berlin, Nice, Brussels and Paris, have been carried out by militants over the past two years.
US President Donald Trump took to Twitter to offer US help to Britain.
French president Emmanuel Macron said on Twitter that "France is standing more than ever side by side with the UK".
At least two French citizens have been injured in the attack, the French president's office said.
- BBC / Reuters / RNZ