Several pedestrians have been injured near London's city's Natural History Museum when a car had mounted the pavement outside the tourist attraction, according to police.
The London Metropolitan Police said the incident in the South Kensington area was not terrorism-related and was being treated as a road traffic collision.
A man has been arrested over the incident.
The pedestrians' injuries are not believed to be life-threatening or "life-changing", police said.
London's ambulance service said they had treated 11 people, mostly for head and leg injuries, with nine taken to hospital.
"We sent multiple resources to the scene, including our hazardous area response team, ambulance crews, paramedics in fast response cars and incident response officers," Peter McKenna, deputy director of operations, said in a statement.
Earlier a BBC reporter at the scene said she could see a car diagonally across the road surrounded by a crowd of people with one or two on the ground.
Shopkeepers in the immediate area were told to evacuate and police established a large security cordon around the area minutes after the incident.
The museum said there had been a serious incident outside and it was working with police.
A museum spokesman told Reuters no one was being allowed into the building and people were being let out through a different exit.
Photographs showed a dented silver car and a man being pinned to the ground outside the museum.
Downing Street said British Prime Minister Theresa May was being briefed on the incident.
London Mayor Sadiq Khan said he was in close contact with the police's most senior counter-terrorism officer.