Armed robbers escaped in a stolen car in an early morning carjacking at the M40 Oxford Services today.

A couple, who are believed to be from Surrey, had pulled in to the Welcome Break Oxford Services on the A418, near Thame, at 12.30am.

Police said a 53-year-old man got out of a silver BMW to use the toilets, while his 63-year-old partner remained in the driving seat.

A dark-coloured VW Golf containing four men pulled up behind their car, blocking it in.

Two men got out and walked over to the BMW and threatened the woman - demanding she get out of the vehicle.

The woman ran into the services, leaving the car with the keys in the ignition.

The two men got into the BMW and drove off, followed by two other men in the VW Golf.

Police said after investigations into the robbery they believed a firearm may have been used.

Det Insp Kev Elkins said: “Further questioning of the victims suggests a firearm may have been used in the robbery. However, as it was not discharged, we are unsure if this was a real firearm or an imitation one.

“Incidents of this type are very rare, and I would like to reassure the community that we are doing everything in our power to ensure these people are caught as soon as possible.”

Police described the first man who hijacked the BMW as black, about 18 years old, six foot tall, with a slim build. He was wearing a grey hooded top.

The second man was also black, while detectives believe there were two other black men in the VW Golf, who remained in that car during the incident.

Det Con Jon Shaw said: “The woman was scared for her safety and has obviously been left badly shaken by the ordeal.

“We believe there may have been other people using the service station at the time of the robbery and we would be very keen to speak with them.

“I would also like to hear from anyone who may have seen these vehicles together after leaving the service station.

“The BMW was a silver-coloured one series 118D SE, registration YG57 OKL.”

Anyone with information should contact police on 0845 8505505 or Crimestoppers on 0800 555 111.