British media reported a car had mounted the sidewalk outside the tourist attraction, one of several large museums in that area of South Kensington, west London, and police said a man had been detained at the scene.
"A vehicle has collided with pedestrians near the Natural History Museum entrance at Exhibition Road," the museum, one of the most popular visitor attractions in the country, said in a statement.
"We are working with emergency services to assess the incident and we are doing all we can."
Police described the incident as a collision.

Several images of the collision were posted on Twitter
A spokeswoman for the London force said counter-terrorism officers were assessing the incident but had not yet reached a conclusion as to the circumstances. Earlier a spokesman told Reuters it was not being treated as a terrorism-related incident at this stage.
A Reuters witness said there were large numbers of police, including armed officers, and paramedics at the scene although the atmosphere appeared calm.
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. She said she was told by police injuries sustained were minor.
A spokesman for the museum told Reuters that no one was being allowed into the building and people were being let out through a different exit.

Paramedics arrived at the scene and attended to the injured
In March, a man drove a car into pedestrians on London's Westminster Bridge killing four before stabbing a police officer to death in the grounds of parliament.
Three Islamist militants drove into people on London Bridge in June before stabbing people at nearby restaurants and bars, killing eight. The same month, a van was driven into worshippers near a mosque in north London which left one man dead.
The Natural History Museum is the fourth most popular tourist attraction in the United Kingdom, with 4.6 million visits during 2016, according to the Association of Leading Visitor Attractions.
© Thomson Reuters 2017
(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)