A van ploughed into pedestrians enjoying a night out in London Bridge, before attackers went from bar to bar stabbing people around Borough Market.
The horrific, brutal attack has been officially declared a terrorist incident.
Since the attack was first reported last night, police officers, paramedics and doctors have been working through the early hours of the morning to help those injured in the attacks.
Here is everything we know so far.
Seven people were killed and 48 seriously injured in the attack.
The emergency services were first called to reports of a white van driving into several people on London Bridge at 10.08pm on Saturday.
The entire area and nearby railway stations were closed, including London Bridge.
Witnesses reported seeing the van driving at around 50mph, mounting the pavement and sweving into a number of people.
Holly Jones, a BBC reporter who was on the bridge at the time, said: ‘A white van driver came speeding – probably about 50mph – veered off into the crowds of people who were walking along the pavement.
‘He swerved right round me and then hit about five or six people.’
The van, which had been driving from north of the river, then drove towards Borough Market – which was especially busy because it was Saturday night.
When it arrived, the suspects stabbed several people in a crowded area. They then reportedly went from bar to bar, attacking people with knives.
Shots were then heard in the area, which was later confirmed to have been police officers shooting the suspects dead.
Met Police later confirmed that seven people had died and at least 48 hospitalised. In addition, the three suspected attackers were shot dead.
British Transport Police said one of its officers was seriously injured responding to the attack.
A third police unit was sent to the Vauxhall area after reports of a stabbing, but this was later confirmed to not be connected to the attacks in London Bridge and Borough Market.
Seven people died in the attack.
London Ambulance Service said it had taken at least 48 injured people to five different London hospitals, while those described as ‘walking wounded’ were treated at the Andaz Hotel near Liverpool Street, where there were paramedics and more armed officers.
A British Transport Police officer who was left ‘seriously injured’ was reportedly stabbed in the face, head, and leg.
Police boats searched the River Thames for anyone who may have fallen from the bridge during the attack.
None of the victims have been named.
Who can you call if you’re concerned about loved ones
Anyone concerned about friends or relatives can call the Met Police’s Casualty Bureau.
Call 0800 096 1233 and 020 7158 0197.
Three men, believed to be the attackers, have been shot by police.
Police said the men were shot within eight minutes of officers receiving the first reports of the attack.
Witnesses described seeing between two and four men getting out of the van after it crashed just south of London Bridge.
A photographer at the scene, outside the Wheatsheaf pub, took a photo of one of the suspects wearing a vest with canisters strapped to themselves.
The vests later turned out to be fake.
The person who took the photo said he then saw three people shot by police.
What’s happening now
The ongoing investigation is being led by the Counter Terrorism Command.
Police say they believe they’ve caught all of the attackers, but armed officers are still sweeping the area.
Officers have been clearing streets, bars and restaurants around Borough Market.
MET POLICE’S FULL STATEMENT
In a statement, the Met Police’s 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.
‘You will understand that our knowledge of the incident is still growing but what we understand at the present time is:
‘At 22:08hrs 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 http://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 Bridge is completely closed and will remain so, British Transport Police said.
Borough station has also been closed. Trains are passing straight through the two stations.
Waterloo East, Charing Cross and Cannon Street stations have also been closed, Network Rail said. Blackfriars has been experiencing delays.
The Thames has now reopened to boats.
Guy’s Hospital, which is in the London Bridge area, has been placed on lockdown as a precaution to keep staff and patients safe. St Thomas’ and the Evelina Children’s Hospital a mile away have also been put on lockdown.