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.
"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." –
Read more at http://www.thestar.com.my/news/world/2017/10/07/man-arrested-people-injured-in-crash-in-london/#BEHG8yfxgjwz95SS.99