At least one person has been killed and several more injured in two terrorist attacks in central London.
A van drove into pedestrians on London Bridge and witnesses described three men stabbing passersby in the nearby Borough Market area.
Here is a timeline of how the events unfolded:
10.08pm: Police are called to reports of a van hitting pedestrians on London Bridge. It is initially unclear whether the van deliberately drove into people but the similarities with the Westminster Bridge terror attack are obvious and armed police are on the scene.
10.30pm: Witness accounts emerge of the van driving into a crowd of people at "about 50mph", leaving at least six casualties on the ground. BBC journalist Holly Jones tells how she narrowly avoided being hit, jumping out of the way of the van. There are unconfirmed reports of people being stabbed and shots being fired.
10.40pm: Police say they are dealing with a major incident and warn people to stay away from the area.
11.15pm: Scotland Yard says it is dealing with a second serious incident in the nearby Borough Market. Three men carrying large knives are seen attacking passersby in the street. People in restaurants reportedly try to fight off the attackers with chairs. Armed and unarmed officers flood the area, telling some people to leave. Video footage in a restaurant in the area shows police telling diners to get down on the floor. Gunshots are heard.
11.30pm: A police officer setting up a cordon tells people to move away from the area and stop filming. Sounding emotional, she says "people have died".
11.45pm: Police say they are searching for three men suspected of carrying out the attacks.
11.50pm: A third incident is reported in Vauxhall, but police later say this is believed to be an unrelated stabbing.
11.55pm: British Transport Police confirm there have been "multiple casualties".
12.10am: Officials say Theresa May is travelling to Downing Street for briefing from security officials and will chair a meeting of the the emergency Cobra committee later on Sunday. She says the incidents are being treated as "potential" acts of terror and praises the emergency services.
12.25am: Both the incidents at London Bridge and Borough Market are declared "terrorist incidents" by police.
1.30am: Three loud bangs are heard in the Borough Market area.
1.50am: A photograph shows two men lying on the ground after being shot by police. One had canisters of some kind strapped to his body.
4am: Police say six people were killed before three suspects were shot dead by armed police. The canisters appeared to be "hoax" suicide bombs. Thirty people are being treated in hospitals around London.
6.15am: London Ambulance Service reports 48 injured people are now being treated in hospitals in the city.
As the London Bridge incident unfolded, the Metropolitan Police issued guidance for the public to follow.
The "run, hide, tell'' advice states:
Run to a place of safety. This is a better option than to surrender or negotiate.
If there's nowhere to go, then hide. Turn your phone to silent and turn off vibrate. Barricade yourself in if you can.
When it is safe to do so, tell the police by calling 999.
The Press Association contributed to this reportReuse content