Britain will vote in a national election on Thursday, just days after militants killed seven people and injured almost 50 in an attack on London Bridge on Saturday night, the third assault in Britain in less than three months.
Seven people are dead and another 21 critically injured after the three Islamic terrorists mowed down pedestrians on London Bridge then stabbed people at random at Borough Market.
The Mayor said: "As Londoners, we will stand together in solidarity to remember those who were killed or injured in this horrific terror attack".
Police received the first reports of the attack at 10:08 p.m. local time.
Turnbull said there are "very real concerns" about their wellbeing. She said more must be done to combat "bigotry and hatred".
Prime Minister Theresa May says Britain must do "more, much more" to fight Islamic extremism.
On Monday, police issued a statement saying a "number of people" were arrested at two properties in east London in counterterrorism raids.
ISIS yesterday claimed responsibility for the attack, which would make it the third ISIS-linked atrocity to hit Britain this year. The assault was claimed by the so-called Islamic State group.
Seven people were killed in the attack, including one Canadian and one French citizen.
All three were shot dead by armed police officers approximately eight minutes after the incident began.
There was a similar hiatus after the attack in Manchester killed 22 people last month.
Borough Market, at the south end of the bridge, is a world-famous food hall and a trendy nightlife area always packed with revellers on a Saturday night.
"As you know, there are around 130,000 Australians living in the United Kingdom at any given time, and many Australian visitors, and there were many Australians in the vicinity of the attack", he said. Evil, evil people, ' he told The Guardian newspaper. Zoido says friends and relatives say Echeverria had confronted a man who stabbed a woman.
He said they were wearing "full gear", adding: "The first bang was nothing like I'd heard before".
An Australian was among those hospitalised, while a Spaniard escaped with light injuries.
French Foreign Minister Jean-Yves Le Drian was due to visit Britain on Monday to speak to the injured French nationals, after President Emmanuel Macron said France was "more than ever at Britain's side".
Grande, who headlined a benefit concert in Manchester on Sunday, alongside stars including Pharrell Williams and Justin Bieber, tweeted that she was "Praying for London".
Saturday night's attack on London Bridge, which left 6 killed and dozens injured, came just days ahead of the election.
US President Donald Trump, "We must stop being politically correct and get down to the business of security for our people".
Mohamed Ozhuparambil lives on the street and said he thinks a Bangladeshi family lives at the house raided by police.
He praised emergency services and said police would make a statement after an emergency cabinet meeting.
May, who served as interior minister for six years before taking office in July after the Brexit vote, said Britain's response to the terror threat must change. "She would have had no understanding of the callous cruelty that caused her death", they added.
The terrorist incident occurred less than a week before the United Kingdom general elections - scheduled for June 8- and a few days after a suicide attacker exploded a bomb in a Pop concert in Manchester, killing 20 people, mostly teenagers.