London terror: Police officer among victims of rampage at Westminster
Four people were killed, including an unarmed police officer, and around 40 others were injured, after a knifeman brought terror to the heart of Westminster during a suspected terror attack.
The attacker, armed with two large knives, mowed down pedestrians with his car on Westminster Bridge, including schoolchildren, then rushed at the gates in front of the Houses of Parliament, stabbing the policeman before being shot dead by other officers.
The fatally wounded policeman, who was unarmed, was named by Scotland Yard's top anti-terror officer Mark Rowley as 48-year-old husband and father Keith Palmer.
Mr Rowley told reporters outside New Scotland Yard, a short distance from the scene of the attack, that the death toll had been updated to five - including Mr Palmer, the suspect, and three members of the public.
Paying tribute to Mr Palmer, Mr Rowley said: "He was someone who left for work today expecting to return home at the end of his shift - and he had every right to expect that would happen."
Some of those hurt have been described as suffering "catastrophic" injuries.
It came as the Prime Minister vowed to defeat what she called "the forces of evil".
She said any attempt to defeat the values that Parliament stood for was "doomed to failure".
Mr Rowley said police believed they knew who the suspect was, but would not go into further details.
Paramedics fought to save Mr Palmer's life, and that of his attacker, on the floor of the cobbled courtyard in front of Parliament, with Foreign Office minister Tobias Ellwood among those who rushed to help.
The police officer was wheeled away on a stretcher with his face covered.
Mr Ellwood, who lost his brother in the Bali bombing, could be seen pumping the officer's chest then standing above him, his hands and face smeared with blood. Armed officers, some in plain clothes and wearing balaclavas, swarmed around the yard just feet from where MPs had earlier attended Prime Minister's Questions.
The knifeman drove a grey Hyundai i40 across Westminster Bridge before crashing it into railings, then running through the gates of the Palace of Westminster.
His attack left a trail of destruction as paramedics tended to victims on the bridge and at the gate.
One woman hit by the attacker's car before he reached Parliament was confirmed dead by a doctor at St Thomas' Hospital. She said others on the bridge suffered "catastrophic injuries".
Another woman who fell into the Thames was rescued and given urgent medical treatment on a nearby pier.
London Ambulance Service said paramedics had treated at least 10 patients on Westminster Bridge.
A party of French schoolchildren were among those targeted on the bridge, with three injured.
Mobile phone footage showed a woman lying lifeless under a bus on the bridge near where the car crashed to a halt.
Donald Trump was among world leaders quick to offer their support.
The White House said the US president spoke to Theresa May in a phone call following the bloody events in London.
Irish President Michael D Higgins is to write to the Queen and London Mayor Sadiq Khan to express the sympathy "of the Irish people with the families of those who have lost their lives and to those who have been injured".
No Irish are believed to have been caught up in the attack.
Eyewitness Rick Longley said: "We were just walking up to the station and there was a loud bang and a guy, someone, crashed a car and took some pedestrians out.
"They were just laying there and then the whole crowd just surged around the corner by the gates just opposite Big Ben.
"A guy came past my right shoulder with a big knife and just started plunging it into the policeman. I have never seen anything like that. I just can't believe what I just saw."
Frazer Clarke, 25, from Burton-on-Trent, one of a group of young boxers who witnessed the attack, said: "We heard a loud bang and screaming and then I noticed some smoke. I thought it was a car crash.
"I looked towards the front gate and people were running, a police officer and a fellow coming to the gate with two knives.
"He was stabbing the police officer with the knives.
"The police officer was stumbling and fell on the floor.
"Another police officer walked toward the guy with the knives and shot him twice."