Northamptonshire Police are appealing for witnesses following an attempted robbery at the BP Service Station, Grange Park, Northampton, in the early hours of Tuesday 5 May.
At about 1.50am, three men entered the shop and demanded staff give them access to the safe. After trying to force open an office door, an alarm was activated and the offenders left the shop. It is believed they made their escape on foot.
The men were all white and wearing dark clothing. Two of the men carried weapons, believed to be a knife and a crow bar.
Witnesses, or anyone who saw anything suspicious in the area around the time of the incident, are asked to call Northamptonshire Police on 101.
Alternatively, they can call the independent charity Crimestoppers anonymously on 0800 555111 or use the anonymous online form at www.crimestoppers-uk.org.