A police officer has been stabbed in the Houses of Parliament in central London, Commons Leader David Lidington has said.
He told MPs the "alleged assailant was shot by armed police" following a "serious" incident.
Staff inside Parliament were told to stay inside their offices.
The BBC's Laura Kuenssberg said police told her someone had been shot and MPs said they heard "three or four gunshots".
Tom Peck, political editor for the Independent, tweeted: "There was a loud bang. Screams. Commotion. Then the sound of gunshots. Armed police everywhere."
Prime Minister Theresa May was seen being ushered into a silver Jaguar car as what sounded like gunfire rang out at Parliament during the incident.
A Downing Street source confirmed that Prime Minister Theresa May was "OK".
An eye witness, Radoslaw Sikorski, a senior fellow at Harvard's Centre for European Studies, posted a video to Twitter purporting to show people lying injured in the road on Westminster Bridge.
He wrote: "A car on Westminster Bridge has just mowed down at least 5 people."
Scotland Yard said it was called to a firearms incident on Westminster Bridge amid reports of several people injured.
Transport for London said Westminster underground station has been shut at the police's request, and buses diverted.
Mr Lidington said: "It seems that a police officer has been stabbed, that the alleged assailant was shot by armed police.
Jayne Wilkinson said: "We were taking photos of Big Ben and we saw all the people running towards us, and then there was an Asian guy in about his 40s carrying a knife about seven or eight inches long.
A policeman has been stabbed and his attacker shot by officers at the House of Parliament Police are treating it as a "terrorist incident" The attacker is reported to have mowed down several pedestrians as he drove a grey Hyundai car across Westminster Bridge before crashing it into railings He is then reported to have run through the gates of the Palace of Westminster and stabbed the officer Eyewitnesses said he was shot by police as he approached a second officer clutching his knife House of Commons and Lords in lockdown - as is nearby St Thomas's hospital Public urged to avoid the area and Westminster Underground station is closed Prime Minister Theresa May was seen being ushered into a silver Jaguar in the grounds of the Palace of Westminster as what sounded like gunfire rang out at around 14:45 GMT A Downing Street source confirmed the prime minster was "OK".
He told MPs the "alleged assailant was shot by armed police" following a "serious" incident.
Staff inside Parliament were told to stay inside their offices.
The BBC's Laura Kuenssberg said police told her someone had been shot and MPs said they heard "three or four gunshots".
Tom Peck, political editor for the Independent, tweeted: "There was a loud bang. Screams. Commotion. Then the sound of gunshots. Armed police everywhere."
Prime Minister Theresa May was seen being ushered into a silver Jaguar car as what sounded like gunfire rang out at Parliament during the incident.
A Downing Street source confirmed that Prime Minister Theresa May was "OK".
An eye witness, Radoslaw Sikorski, a senior fellow at Harvard's Centre for European Studies, posted a video to Twitter purporting to show people lying injured in the road on Westminster Bridge.
He wrote: "A car on Westminster Bridge has just mowed down at least 5 people."
Scotland Yard said it was called to a firearms incident on Westminster Bridge amid reports of several people injured.
Transport for London said Westminster underground station has been shut at the police's request, and buses diverted.
Mr Lidington said: "It seems that a police officer has been stabbed, that the alleged assailant was shot by armed police.
A vehicle used against pedestrians.
A stabbing attack.
Another fucking Muslim.
http://www.independent.ie/world-news/eu ... 55655.html
and the metro system.
What we know so far
A policeman has been stabbed and his attacker shot by officers at the House of Parliament
Police are treating it as a "terrorist incident"
The attacker is reported to have mowed down several pedestrians as he drove a grey Hyundai car across Westminster Bridge before crashing it into railings
He is then reported to have run through the gates of the Palace of Westminster and stabbed the officer
Eyewitnesses said he was shot by police as he approached a second officer clutching his knife
House of Commons and Lords in lockdown - as is nearby St Thomas's hospital
Public urged to avoid the area and Westminster Underground station is closed
Prime Minister Theresa May was seen being ushered into a silver Jaguar in the grounds of the Palace of Westminster as what sounded like gunfire rang out at around 14:45 GMT
A Downing Street source confirmed the prime minster was "OK".
He was a block away when it happened. With video.
One woman confirmed dead.
One woman confirmed dead.
Second death, a police officer.
You can see the knife by his feet.
A man, believed to be the attacker, is put on the stretcher and wheeled into an ambulance inside the grounds of Parliament
You can see the knife by his feet.
It should be shoved up his ass like he deserves.
A group of teenage kids from France on a school trip are on the injured list.
Now rumblings about second attacker.