There are reports of a number of casualties after an incident possibly involving a vehicle and a knife in the London Bridge area of the capital, British Transport Police has said.
Police say armed officers responded to reports of a van hitting pedestrians on the bridge in central London.
The Metropolitan Police said armed officers were also at the nearby Borough Market.
A BBC reporter at the scene says police are searching for three suspects.
It said “multiple resources” are in attendance.
Downing Street said: “The prime minister is in contact with officials and is being regularly updated on the incident at London Bridge.”
Transport for London said the bridge has been closed in both directions due to a “major police incident”.
Bus routes were being diverted and the neighbouring Southwark Bridge has also been shut, it added.
TfL said there were further closures in Borough High Street, where armed police were later seen. On the north side of the river, Lower Thames Street was closed.
London Ambulance Service tweeted: “Multiple resources attending an incident at #LondonBridge, please avoid the area”.

source: bbc.com