Two customers who left a Bicester shop shortly before it was robbed may be vital witnesses, police said.

Officers are still hunting two robbers who forced staff to hand over cash at gunpoint at McCoull's in Villiers Road, at 6.40am, shortly after opening up, on Thursday.

The men, who wore balaclavas, led a woman in her 60s and a women in her 20s into the back office where a man, in his 20s, was working. Staff were forced to hand over hundreds of pounds from the safe.

One of the robbers had a handgun and the second carried a canister, believed to be CS spray.

Detectives would like to speak to anyone who saw anything suspicious and said customers who left the store shortly before the robbery may provide vital information.

Det Insp Simon Morton, of Witney CID said, said: "This was a terrifying experience for the staff and they are obviously very shaken up by what happened.

"There may have been people coming home from night shifts or making their way to work who saw the the offenders running along the footpath on Villiers Road or climbing into a getaway car. We would urge them to come forward and help us catch the robbers."

The first robber was in his 20s, 6ft 2in tall, and stocky. His accomplice was in his late 20s and 6ft 4in tall. Both men wore black woollen balaclavas, black nylon bomber jackets and khaki combat trousers.

Anyone with information should call 01865 846000 and ask for the control room, or call Crimestoppers on 0800 555111