Man arrested, people injured in crash: police

Crowds in the busy tourist spot in South Kensington, which is also home to the Victoria & Albert Museum and the Science Museum, fled screaming in panic, an AFP reporter said.

Armed police were at the scene, and a video posted on Twitter showed a man being held down on the road next to a black car that appeared to have crashed.

Security is high in Britain after five terror attacks in six months -- four of them in London and one in Manchester -- with the bloodshed claiming 35 lives.

London's Metropolitan Police said they were called to the scene at 2:21 pm (1321 GMT) after reports of a collision.

"It is believed that a number of pedestrians have been injured. A man (no further details) has been arrested at the scene," the police said in a statement.

"Enquiries to establish the circumstances and motive are under way."

A spokesman for the museum told AFP: "I can confirm that there has been a vehicle collision with pedestrians on our Exhibition Road entrance."

One witness, who gave his name only as Leonard, told AFP: "I was near South Ken station and there were many police.

"Suddenly a police woman officer shouted at the crowd to run, and everybody flew in panic, many people screaming."