The BBC's Nick Quraishi at the scene says he is now able to corroborate earlier reports of gunshots being fired.
Reports suggest it may have been more than one incident:
- A van hitting people at London Bridge and three people then jumping out of the vehicle and attacking members of the public;
- A separate incident at Borough Market
- Police have now said they are responding to a third incident in Vauxhall
It is understood that police are looking for three suspects who may be armed.
