A spokesman for the business said he is relieved nobody was hurt in the incident, but it isn’t known whether cash or goods were stolen in the raid.
Post Office services will not be available at the Main Road outlet today, but should be resumed on Monday.
The business’s shop remains open.
At least half a dozen police vehicles are said to have been on the scene this morning, and investigations are continuing locally.
Anyone with information on the raid, which happened some time before 4am, should contact police via 101.