A terrorist wearing a fake suicide vest who went on a knife rampage in central London killing two people has been shot dead by police.
The attacker, who has not been named, was killed on London Bridge on Friday afternoon in full view of horrified onlookers.
Metropolitan Police Commissioner Cressida Dick confirmed two people died, and three others were injured.
The knife attacker shot dead on London Bridge was known to police and had connections to terror groups, according to new reports.
NHS England said one of the three injured victims was "critical but stable" while another is stable. The third victim has less serious injuries.
Prime Minister Boris Johnson praised members of the public "for their immense bravery" after it emerged bystanders helped tackle the suspect to the ground and disarm him.
Mr Johnson called a meeting of the Government's emergency committee Cobra on Friday evening and cancelled his General Election campaigning events on Saturday.
Several people were stabbed by the knifeman before he was grappled to the ground and disarmed by members of the public.
Footage on social media appeared to show armed officers surround a person on the ground before discharging a weapon, while a bystander appears to remove a large knife from the scene.
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The eyewitness video appears to show a man being shot on the pavement of the north-bound carriageway on the western side, near Fishmongers' Hall.
Witnesses described a scene of panic around London Bridge, moments after the incident.
National Rail tweeted: "London Bridge station has now reopened following an earlier police incident near the station. Trains may continue to be delayed, cancelled or revised whilst the train service is reinstated."
Prime Minister Boris Johnson said: "I'm being kept updated on the incident at London Bridge and want to thank the police and all emergency services for their immediate response."
He has cancelled his General Election campaigning events on Saturday and will instead focus on overseeing the response to the London Bridge attack.
The Chief Constable of the PSNI praised the Met Police for their actions.
Witness Kelby McNally, OK! Online's editor, works in the Northern and Shell Building on Lower Thames Street near to London Bridge, said she initially thought a fire alarm had gone when she saw "loads of people just running".
She told the PA news agency. "There were loads of people just running, I thought it was a fire alarm or something, and then I saw two girls from my office who told me not to go back there.
"I asked what had happened, and they said they had heard gunshots and now everyone is running."
Home Secretary Priti Patel wrote on Twitter: "Very concerned by ongoing incident at London Bridge. My thoughts are with all affected. I am grateful for the rapid response of our police and I urge everyone to follow their advice."
Footage from the scene appeared to show a white lorry straddling the northbound and southbound carriageways.
The video shows several officers surrounding the vehicle before moving to the rear to check its container.
London buses can be seen either side of the lorry while three police cars are parked next to it on the bridge.
Nurse Jackie Benfield, 32, described how she asked to be let off a bus on London Bridge after she heard "five or six" gunshots.
Ms Benfield, who was on her way home from work, said she exited the bus and "ran like hell" to escape the shots.
Connor Allen, who was in his van on the bridge when it was evacuated said: "Everyone just started running, you heard these pops and that was it. We just got out the van and started running."
One business owner said she had been crossing London Bridge to get to her shop on the north side when police officers stopped her.
She said that was when she heard at least five or six gunshots and said that her store has been evacuated.
The woman, who wished to remain anonymous, said: "We heard shooting, it was about five or six shots, I heard five or six quite clearly.
"All my staff have been evacuated."