A woman has died and a police officer has been stabbed at the Houses of Parliament in London, in what police are treating as a terrorist incident.
The attacker, who was shot by officers, is reported to have mowed down several pedestrians as he drove a car across Westminster Bridge.
IBTimes UK reporter Ian Silvera was at the scene outside Westminster speaking to eyewitnesses.
Michael Mitchell, who was working on the corner of Westminster Bridge next to the Houses of Parliament, said: "I was up the road, I didn't witness anything, but we just abandoned our car after it happened.
"A guy in the car in front said that people had been mown down. We were coming down at about 2.45pm when they started evacuating the nearby buildings, we'd just come around the corner and the SWAT team turned up and we just had to evacuate."
A man who was working nearby said: "After it happened I had just arrived and I was told we had to go away because it was too dangerous.
"Personally, I'm not shocked, but I'm shocked by this news. Recently a lot of terrorist attacks have happened in Europe, but I think this is the first one in the UK."
Tawhid Tanim, a sales consultant, was on a break and stood by the entrance to Westminster tube station at the time. He said: "All of a sudden all I could hear was 'bang, bang, bang' about five or ten feet away from me and people just started running away and I didn't know what was happening.
"I had gotten a little bit further a saw a car had smashed into the wall and people started running all over and literally a few seconds after police were saying 'move, move, you have to move', we just started running, I could have lost my life or something.
"I had that feeling that I'm going to die. All I could see was that a car was smashed into the Parliament wall and looked like a person under the car and some people were trying to help.
"I could see something was happening on Westminster Bridge as well and the police just shouted 'run, run!'
"All I could see was someone trying to help someone under the car."
SNP MP Chris Law was one politician who was evacuated from the scene. At the time of the attack the division bills were ringing inside parliament as a vote was due to take place. He said: "We heard one or two bangs and were asked to move out safely. Obviously, we're all very shaken and shocked, nothing prepares you for this."