A small sum of cash was taken

Gardaí have arrested four people after an armed robbery at a petrol station in Co Carlow.

It happened on the M9 shortly after 2.30am this morning when two men, one armed with a gun and the other with a knife, entered a filling station at Tinryland.

They threatened staff and one shot was fired - but no one was injured.

They made off in a dark-coloured Volkswagen Golf with a small sum of cash.

During a follow up operation shortly after 9.00am, gardaí carried out a search at a house in Carlow town.

Three men and one woman - all understood to be aged in their 20s - were arrested.

They are being held under Section 30 of the Offences against the State Act at Carlow station.

Gardaí are appealing to anyone in the filling station or the surrounding area between 2:00am to 2:30am to come forward.

They can contact Carlow garda station on 059-913-66220 or the Garda Confidential Line at 1800-666-111.

Investigations are on-going.