FAST-food giant McDonald's has put up a £500 reward to help catch a pair of armed robbers who subjected the pregnant manager of the Chippenham restaurant to a terrifying ordeal.

It is 10 months since the raiders struck at the Bath Road restaurant, forcing the manager to open the safe and hand over £3,000 at gunpoint. Police hunting the culprits have renewed their appeal for help, and say someone in Chippenham will know who is responsible.

Detective Sergeant Paul Kessell said: "This was a particularly nasty incident. It was even more vicious because the manager was pregnant. I believe it's someone local to Chippenham and I'm sure they must have disclosed what happened to others."

Now franchise owner David Williamson has offered a £500 reward for information leading to a conviction. The attackers targeted the restaurant at around 7am on June 26, moments after the staff had opened up.

The staff had left the front door unlocked and the robbers, who were wearing stockings over their heads and brandishing a black handgun, walked in and ordered two teenagers to lie face down on the floor. The 17-year-old boy and 18-year-old girl, who both work in the restaurant part-time, were tied up with cable tie.

Their arms and legs were bound as the manager, who was six months' pregnant at the time, was ordered to open the safe. The pair bundled the cash into holdalls and calmly walked off along a footpath into Cepen Park South.

The whole incident was over in minutes and the victims made a 999 call at 7.10am. No-one was hurt, but the workers were severely traumatised. DS Kessell said: "Public support is critical to solving this crime. We want to hear about anyone acting unusually around that time.

Someone may have overheard a conversation about the incident or a person using lots of coins to pay for things. "I appreciate it's a very long time ago but there were a significant amount of coins stolen in fabric bags."

The suspects were wearing blue overalls and are described as white and aged between 20 and 30. One was about 6ft and the other 5ft 8ins. Police have prepared an artist's impression of one of the men involved.

Anyone with information should contact Chippenham Police on 08454 087000.