A crash involving a car has taken place by the barriers outside the Houses of Parliament earlier this morning.
An armed response team is on the scene, as well as a significant emergency services presence.
The man driving the car has been arrested.
Metropolitan Police tweeted: '˜At 0737hrs today, a car was in collision with barriers outside the Houses of Parliament.
'˜The male driver of the car was detained by officers at the scene. A number of pedestrians have been injured. Officers remain at the scene.
'˜We will issue further info when we have it.'
Police don't believe that anyone is in a life-threatening condition '“Â but cordons are in place to assist with the investigation and Westminster tube station is currently closed.