Armed robbers punched a man in the face after he refused to hand over his mobile phone during a heist in Banstead, Surrey.

Police are appealing for information about the raid on the Threshers off-licence in Nork Way on Sunday.

Detectives said two men, including one brandishing a small black handgun, entered the off-licence just after 7pm and ordered the shop manager to open the store safe.

When the store manager told the robbers that the safe had a time-delay on it they ordered the staff to open the tills and put the money in a bag before also stealing a mobile phone.

As the men left the shop they were confronted by a waiting customer.

The robbers demanded his mobile phone, and when the man refused, punched him in the face.

Two off-duty Thames Valley police officers spotted the men fleeing the off-licence and chased them, but the robbers disappeared into a nearby residential area.

Investigating officer, Detective Constable Claire Langley, said: "This has left both victims traumatised and we urgently need to find the men responsible.

"I would like to speak to anyone who was in the area at the time who may have seen the men prior to the robbery or as they left the off-licence."

The offender carrying the gun is described as black, aged about 20, approximately 6ft tall, slim build, clean shaven, a south London accent, wearing a hood and a balaclava and a beige jacket.

The second man was also black, wearing a dark jacket with the hood up, light blue jeans, around 5ft 8 to 5ft 10 tall, about 20 years old with a slim build and a south London accent.

Anyone with information is urged to contact DC Langley at Caterham CID on 0845 125 2222 or Crimestoppers anonymously on 0800 555 111.