Six people were killed in the terrorist attacks on London Bridge and the nearby Borough Market before three suspects were shot dead by police, Scotland Yard has said.
Mark Rowley, the Assistant Commissioner of the Metropolitan Police, urged people to “remain vigilant” and to stay away from the two areas to enable emergency services to deal with the incident.
He confirmed they were being treated as terrorist incidents with the Met's Counter Terrorism Command leading the investigation.
One of the people who was stabbed was British Transport Police officer who was responding to reports of a van hitting pedestrians on London Bridge.
The officer received “serious but not life-threatening injuries”, Mr Rowley said.
“Armed officers responded very quickly and bravely, confronting three male suspects who were shot and killed in Borough Market,” he added.
“The suspects had been confronted and shot by the police within eight minutes of the first call.
“The suspects were wearing what looked like explosive vests but these were later established to be hoaxes.”
In a statement issued at about 4am on Sunday, Mr Rowley said it was believed that six people had died “in addition to the three attackers shot dead by police”.
“And at least 20 casualties have been taken to six hospitals across London,” he said.
He said the attacks began just after 10pm on Saturday when a van hit people on London Bridge.
It then drove to Borough Market, where the attackers left the vehicles and “a number of people were stabbed”.
Mr Rowley urged anyone with images or film of the incidents to pass them to police by uploading it at www.ukpoliceimageappeal.co.uk.
“Our thoughts are with all those involved and those responding to both incidents. Those who are concerned about a loved one can contact the Casualty Bureau on 0800 0961 233,” he added.
“We are reviewing and planning to strengthen our policing stance across London over the forthcoming days, and there will be additional police and officers deployed across the Capital.
“I would like to ask the public to remain vigilant and let us know if they see anything suspicious that causes them concern and dial 999 immediately.”