LONDON - The leader of Britain's House of Commons says a man attacked a police officer at Parliament and has been shot by police.
The head of counterterrorism at London's Metropolitan Police, says four people have died in the terror incident, including an attacker and a police officer. David Lidington says the Parliament complex is in lockdown. London police say they are treating a gun and knife incident at Britain's Parliament "as a terrorist incident until we know otherwise."
There are also reports of a vehicle hitting pedestrians on nearby Westminster Bridge.
The Metropolitan Police says in a statement that the incident is ongoing. It is urging people to stay away from the area.
The former Polish foreign minister Radoslaw Sikorski posted a video on Twitter that seems to show people lying injured in the road on Westminster Bridge.
Sikorski, a senior fellow at the Harvard Centre for European Studies, says he saw at least five people lying on the ground after being "mown down" by a car.
Sikorski told the BBC he "heard what I thought what I thought was just a collision and then I looked through the window of the taxi and someone down, obviously in great distress.
"Then I saw a second person down, and I started filming, then I saw three more people down, one of them bleeding profusely."
A European security official says there was increased chatter on jihadi networks Tuesday following the UK's adoption of an electronics ban aboard flights from certain mostly Muslim countries. He said, however, there was no information that the incident was terror-related. The official spoke on condition of anonymity because he was not authorized to speak about ongoing security operations.
White House Press Secretary Sean Spicer said President Donald Trump has been briefed on the situation.
Incident in #Westminster: We are treating this as a terrorist incident until we know otherwise— Metropolitan Police (@metpoliceuk) March 22, 2017