Two masked men threatened and robbed security guards in Maldon, Essex on Tuesday.
The guards were putting money into the cash machine at the Safeway store in Wick Hill at 1015 BST, when they were threatened by the men.
One of the robbers was armed with a hand gun.
The guards were forced to hand over thousands of pounds of cash intended for the machine.
After a brief scuffle with two members of shop staff, the two robbers were driven away by a third man in a blue Audi, registration number NUO2 JYD
The car headed in the direction of Chelmsford on the A414.
Police have appealed for help in tracing the vehicle, but said the men were dangerous and should not be approached.