Police are appealing for information after two men reportedly robbed the Co-op store in Ancaster.
The men entered the store on Ermine Street just after 10.30pm on Wednesday, May 30 and demanded money from a member of staff in the supermarket.
Police said the men made off with a quantity of cash.
Nobody was injured during the incident.
The Ancaster Co-op Facebook page has apologised to customers and told them it will be closed this morning until further notice
One local resident told Lincolnshire Reporter that on the morning of May 31 a police cordon was in place around the premises.
Lincolnshire Police are now trying to trace the suspects and are asking anyone who saw something suspicious, including suspicious vehicles, to contact them via email or on the non-emergency number 101, quoting incident 452 of May 30.