Shaky video of commotion after Parliament shooting. pic.twitter.com/ofGZwcMgaA
— Patrick Daly (@thepatrickdaly) March 22, 2017
Gun fire has been heard outside Westminster after a man wielding a knife was seen in the area.
At least a dozen people have been injured, according to Reuters.
There's been a shooting / stabbing at Parliament. Stay safe everyone. pic.twitter.com/Fb2LNXfLh5
— Luke Steele (@Lukesteele4) March 22, 2017
The Press Association said two people were seen lying within Old Palace Yard, immediately outside Westminster Hall.
Sky's Tamara Cohen said the Prime Minister was "bundled out by [a] plain clothes policeman" when the news broke.
MP trapped in chamber says the Prime Minister was in the division lobby when it happened, bundled out by plain clothes policeman
— Tamara Cohen (@tamcohen) March 22, 2017
The Huffington Post UK's Owen Bennet, who was in Parliament at the time, said:
"I heard what sounded like an explosion and raised voices outside Parliament, and so I rushed to the window.
"I saw people running past the entrance to the New Palace Yard entrance to Parliament, and then at least one person try to run into the Yard itself. A police officer chased this person and wrestled them to ground.
"Shots were then fired, but I can't remember how many and I didn't see who fired them.
"I ran down the stairs from my office overlooking the Yard to get more information, but the police prevented us from leaving the stairwell.
"When I returned to my office, I could see two people lying on the ground outside Westminster Hall, but neither of these were the person I saw wrestled down by the police officer minutes earlier."
Other political reporters based in the area shared their version of events:
Emergency services trying to revive an individual lying on pavement some way away from entrance to parliament on Parliament Street. pic.twitter.com/bmytpXZ11p
— Jim Waterson (@jimwaterson) March 22, 2017
Shots fired outside Parliament. Loud explosion then shooting. Man lying shot outside gates to Parliament. Gun shots outside, Frightening.
— Christopher Hope (@christopherhope) March 22, 2017
Just seen police shoot a man outside parliament, appeared to be wielding a knife
— Charlie Cooper (@CharlieCooper8) March 22, 2017
The House of Commons has also reportedly been suspended.
This is the moment Parliament was suspended as "sounds similar to gunfire" were heard outside pic.twitter.com/to6PPxkNqL
— Sky News (@SkyNews) March 22, 2017
An air ambulance has reportedly been scrambled to the scene.
Air ambulance just landed at Parliament Square, Westminster, dozens of police cars pic.twitter.com/TZVTO6IzDR
— Peter Yeung (@ptr_yeung) March 22, 2017
This is a breaking news story and will be updated. Check back for the fullest version. Follow The Huffington Post UK on Twitter here, and on Facebook here.