Authorities said they are still working to establish the circumstances and motive surrounding the incident.
"11 people were found at the scene with varying injuries and nine of them have been taken to hospital, and this includes the man that was detained by police", Metropolitan Police said.
Police confirmed that a vehicle mounted a pavement outside the museum on Exhibition Road in South Kensington shortly before 2.20pm today.
Police have already said that the incident was not terror-related.
A man has been detained but not formally arrested, the police said.
A spokesman said the incident, which unfolded around 2:20 p.m. local time, was not being treated as terrorism-related at this stage. An image and footage of a man being restrained by four people emerged on twitter.
In a statement to the police stated that injured several pedestrians, however, the BBC correspondent from the scene said their injuries were minor.
However, the Met later said its inquiry was "entirely a road traffic investigation".
The ambulance service sent multiple resources to the scene, including its hazardous area response team, ambulance crews, paramedics in fast response cars and incident response officers.
The incident took place in one of London's most popular tourist destinations.
According to her, the scene immediately arrived armed police, in the sky circling police helicopter.
Britons in general, and Londoners in particular, have been jumpy after a string of extremist attacks this year, including deadly attacks using vehicles to hit pedestrians on Westminster Bridge and London Bridge.
The UK is now under a "severe" level of threat of terror attack, according to the MI5 Security Service's rating system.
The Royal Albert Hall, which has heavy bollards erected outside its entrance, is also in the area.
In a message on Twitter, the Prime Minister said: "My thanks to the first responders at this incident this afternoon and the actions of members of the public".