Counter-terrorism police in Britain are investigating a car crash in a popular tourist area of London after several people were injured.

A black Toyota mounted the pavement outside the Natural History Museum in South Kensington.

Images show someone being pinned down by security guards, and officers have confirmed they've detained a man.

But there's no word yet on whether the crash was deliberate.

Witnesses report seing people running from the scene as police tried to evacuate the area - it still remains cordoned off.

Downing Street says the Prime Minister is being kept up to date with developments.