A four-man gang broke into the post office at Upper Ormond Quay in Dublin yesterday after digging a hole in the building from the disused Ormond Hotel next door.
A member of staff arriving for work at the post office was confronted and threatened by one of the gang members, who escaped with a bag of cash.
Gardaí said they want to speak to anyone who saw two men wearing high-visibility jackets who were acting suspiciously outside the former hotel at about 8am yesterday.
They are also seeking information on two other men who were seen wearing motorcycle leathers in the same area at about 9.20am.
After stealing the cash, it is believed they sped off from the scene on motorbikes in the direction of Smithfield Markets.
“No firearm or violence was used during the incident and no persons were injured,” the garda spokesman said.
Anybody with information is asked to contact the Bridewell Garda Station on 01-6668200, or call the Garda Confidential Line on 1800-666-111
Meanwhile, gardaí are carrying out searches in North Cork for two men who escaped on a motor- cycle after failing to rob a post office.
Gardaí have appealed to the public to be on the lookout for a white motorcycle with a red stripe which the criminals may have stashed in an isolated location.
A garda spokesman said that the men attempted to hold up the post office at Rathcoole, between Millstreet and Banteer.
One of the would-be raiders went inside and demanded money from the owner, while the other stood guard at the door.
But the owner refused to hand over any cash and the men fled. Both were described as wearing dark clothes and had their faces covered.
As they sped away on the motorbike, which gardaí believe may have been a small Yamaha, one of the men donned a blue helmet.
The attempted post office robbery happened at about 11am on Thursday.
It is believed that the pair, who were described as being both 6ft tall and of strong build, fled in the direction of Banteer.
One was said to have a Dublin accent and the other a Cork accent.
Anybody with information is asked to contact Kanturk Garda Station on 029-20680.