Police have blocked off Twickenham town centre after two robbers attacked a guard delivering money to a bank.
Officers erected a cordon around HSBC, in London Road, following the raid at lunchtime today.
The robbers punched the cash-in-transit guard in the face before snatching a money box he was carrying.
Acting Chief Inspector Hannah Wheeler, of Richmond police, said the two robbers fled on foot.
She said: “They punched the delivery man in the head and made off.”
Police said the robbers were both black, wore woolly hats and used scarves to cover their faces.
They were wearing dark clothing, were of slight build and were believed to be aged in their mid 20s.
Witnesses said they saw a car speed away from the scene and officers have been working to find out if it was connected to the robbery, police said.
A spokeswoman for G4S said its guard was outside the bank just after midday when the robbers punched him in the face.
She said: “He has some bruising to the face but he is ok.”
A spokeswoman for HSBC would not reveal how much money the robbers got away with, but said the bank would hand its CCTV footage to police to help with their inquiries.
She said: “All staff are absolutely fine, we are helping police with their investigations.”
She said the bank was due to re-open this afternoon.
Anyone with information should call Crimestoppers on 0800 555 111.