An armed man is believed to have taken hostages in an incident at a bank, police have said.
Surrey Police said the man went into Barclays in Church Road, Ashford, west London, shortly before 4pm.
A spokeswoman said: "A number of people were inside the bank at the time and currently the man is still believed to be inside the premises.
"It is believed that there are still people in the bank."
Officers assisted by a helicopter were on the scene and assessing the situation. Church Road and Fordbridge Road have been closed.
Detective Superintendent Alan Sharp said: "Police were on the scene in Church Road within minutes and are assessing the situation.
"Public safety remains our first priority and we are advising people to stay away from the area at this time. We will provide you with further updates in due course."
Shafiul Alam, 26, a waiter in a nearby Indian restaurant called Peppers, said: "I was around there this afternoon and there was a lot of police activity. There is still a police helicopter circling overhead.
"I'm shocked to hear that the incident is still going on. It is a very quiet bank, with not many staff in it.
"Ashford is a quiet place compared to other towns around here such as Staines and Feltham."