Gardaí in Killarney are investigating a third incident at a premises housing a post office near the town in Co Kerry.
The burglary at the shop in Glenflesk, where the local post is located, took place at approximately 1.30am on Monday.
Criminal damage occurred and a number of items were taken from the property, Gardaí have confirmed.
The burglary follows a similar incident at nearby Headford Post Office in the early hours of Friday morning and the attempted robbery of Killarney Post Office at around 10.30am the same day.
Gardaí were keeping an open mind as to whether the two incidents on Friday were linked, however, at this point they do not believe there is a link to the third case.
A black Toyota car and shot gun involved in the attempted robbery of the main Killarney Post Office have been recovered and Gardaí are concentrating their search efforts on the town, where they believe the suspects are hiding.
Anyone with information in relation to the incidents is asked to contact Killarney Garda station on 064-667 1160, the Garda Confidential Line on 1800-666 111 or any Garda station.
An Post said it does not comment on security issues.