Officers from Chester Local Policing Unit are currently dealing with an incident on Main Street, Frodsham.
Shortly before 8.30am on Wednesday 1 June police received reports of a robbery at the Post Office on Main Street, Frodsham.
Two men, believed to armed with a handgun, entered the store and threatened staff before fleeing the scene. There are no reports of any injuries.
Officers, including armed patrols, remain in the area and enquiries are ongoing.
Anyone with any information is urged to call Cheshire Police on 101 quoting incident number 167 of 1st June. Information can also be passed on anonymously, via Crimestoppers, on 0800 555 111.