The incidents occurred at London Bridge and Borough Market when in one of the attacks a white van ploughed into pedestrians on London Bridge at about 10.08 pm, said reports.

The suspects reportedly also stabbed people and a police officer after jumping out of the van.

More than 30 people were injured.

"This is for Allah," said one of the terrorists stabbing a girl, said an eyewitness speaking to The Telegraph.

London's Metropolitan Police confirmed six deaths.

Assistant Commissioner Mark Rowley said:“Since late yesterday evening [Saturday, 3 June], the Metropolitan Police Service has been responding to incidents in the London Bridge and Borough Market areas of south London. We are treating this as a terrorist incident and a full investigation is already underway, led by the Met's Counter Terrorism Command."

"At 22:08 hrs yesterday evening we began to receive reports that a vehicle had struck pedestrians on London Bridge. The vehicle continued to drive from London Bridge to Borough Market. The suspects then left the vehicle and a number of people were stabbed, including an on-duty British Transport Police officer who was responding to the incident at London Bridge. He received serious but not life-threatening injuries. His family has been informed."

"Armed officers responded very quickly and bravely, confronting three male suspects who were shot and killed in Borough Market. 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."

“The ongoing operation is led by the Met, working closely with British Transport Police, City of London Police, the London Ambulance Service and the London Fire Brigade.

“At this stage, we believe that six people have died in addition to the three attackers shot dead by police. And at least 20 casualties have been taken to six hospitals across London.

“I'd like to repeat our request for the public to avoid the following areas: London Bridge and Borough Market. This is to allow emergency services to deal with this incident.

“The investigation is being led by the Counter Terrorism Command and we would ask anybody who has images or film of the incident to pass those 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.

“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.”

London's first Muslim mayor Sadiq Khan urging all to remain calm said: "The Metropolitan Police are responding to the horrific terrorist attack at London Bridge and Borough Market. My thoughts are with everyone affected."

"The situation is still unfolding and I would ask all Londoners and visitors to our city to remain calm and vigilant. Please report anything suspicious to the police, but only call 999 in an emergency," he said.