A van has mounted the pavement and ploughed into pedestrians on London Bridge in the centre of the British capital, leaving several people injured.
The Metropolitan Police has confirmed it is dealing with a serious incident, although the precise details are still emerging. The Met has also said it is dealing with a separate incident at Borough Market, just yards from London Bridge.
Eyewitnesses report that there has been a stabbing and shots fired, although specific details are still emerging.
Sources quoted by Sky News have reported the incident is being treated as a terrorist attack.
A journalist for the Sun, whose offices are just yards from London Bridge and overlook Borough Market, reports seeing one man being led away by police in handcuffs.
London Bridge is closed in both directions as a result of the incident. Police boats were reportedly looking for people who may have been thrown off the bridge.
More to follow.