Several people have been injured after a car hit pedestrians near the Natural History Museum in London, police say.
The Metropolitan Police said one person had been detained following the incident at 14:20 BST in Exhibition Road in South Kensington.
Video footage that emerged on Twitter showed a man being restrained on the ground.
London Ambulance said it treated 11 people, mostly for head and leg injuries. Nine were taken to hospital.
Police have not indicated the nature of the incident, saying inquiries are under way to establish the circumstances.