A woman heard her mother being held up at knifepoint behind the counter of a petrol station in Calne when her ordeal was relayed over her mobile phone.

The garage worker had been talking to her daughter on the phone when the robbers walked in with their faces covered and hoods up.

She dropped her phone behind the counter and while she was forced to hand over £490 in cash and £300 worth of cigarettes, her daughter called the police.

The drama happened on Tuesday last week at 9.30pm at the Murco Petrol Station in Oxford Road.

The garage worker, a woman in her 40s, was left shaken after her ordeal, and has not been back to work since, except to pick up her belongings.

A close friend of the woman, who asked not to be named, said it was lucky her daughter was on the phone at the time.

She said: “Had she not been on the phone they may not have found them, because they could have been home by then.

“Her mother said to her ‘I don’t like the look of those two coming in’ she heard a muffled sound when her mother put the phone under the counter and then she heard her mother screaming.

“They kept shouting and shouting at her saying ‘fill the bag or we will slit your throat’. Of course she was crying throughout the whole thing.

“The panic button is quite a distance from the till where she was standing. They knew where the panic button was and they stopped her from reaching it.

“When people are on their own the doors should be locked. It shouldn’t be allowed to happen again – they need to do something about it.”

Petrol station manager Thuraisingam Yogamoorthy said: “I saw her the following day and she was still crying and panicky. We were all really shocked about it, but nobody was hurt, that’s the main thing.”

Normally Mr Yogamoorthy works at night, but on that particular day the woman had asked to work later because she wanted to go somewhere in the morning.

Police have released CCTV images of two individuals they want to identify in connection with the incident.

The male carrying the knife is described as white and wearing a dark or green hoody, shorts or rolled-up jeans, with a distinctive white logo on a rear pocket, and dark ankle boots.

The second male is also described as white and was wearing a dark hoody, black tracksuit bottoms with piping down the leg and white trainers.

After the robbery both males headed out of the shop and made off on foot in the direction of Porte Marsh Road. Police, including a dog handler and the force helicopter, searched the area for nearly two hours.

A knife was recovered and a teenager was arrested in Oxford Road on suspicion of robbery. A second teenager was arrested, also on suspicion of robbery, the following morning.

Another member of staff at the garage, Mary Giles, experienced a similar incident when she first started working there 12 years ago.

She said: “They see a woman here and we’re vulnerable. When I first came here I was robbed. The chap had a knife to my stomach and he said to give him the money.

“He went to prison or youth custody because he was only 16. To be honest with you, women should not be on their own at night.”

Both teenagers are 17-year-olds from Calne and they were released on police bail the following night, to return to Melksham Police Station in October. Anyone with information can contact DC Tom Allen at Melksham CID on 101. or Crimestoppers on 0800 555 111.