At approximately 1.50pm on Sunday August 17 two men entered Threshers on Station Road, Princes Risborough and attempted to steal the cash register but made off empty handed. It is believed that they sped off in a Volkswagen Golf that was parked near to the shop.

Both men covered their faces and one man was in possession of a weapon.

Later that day, at approximately 4pm, a man wearing a black hooded top entered Threshers in School Road, Penn, and stole a cash till monitor and charity boxes. He ran off towards High Wycombe.

DC Neil Chapman, investigating the crime, said: "We believe that these two incidents are linked and I urge with any information at all to get in touch with me at High Wycombe police station on 0845 8 505 505."

If you don't want to talk to police or don't want to leave your name call the Crimestoppers charity on 0800 555 111.

You can also give information to the police in person by visiting any police station.