A man armed with a knife threatened staff around 8pm before making off with a small sum of cash.
It’s the third such incident in four days.
The PSNI say two men were arrested in Strabane last night after a cross-Border operation involving Gardai.
It’s understood the men held are ‘known’ to police forces on both sides of the Border.
A small sum of money was taken in the latest raid but no-one was injured.
It follows the attack on the Arthur sisters on Monday and a garage raid in Lifford on Tuesday.
Cllr Frank McBrearty has condemned the latest robbery and called on senior Gardai to review their strategies for dealing with crime along the Border.