An ATM was smashed and tens of thousands of euro reportedly stolen during a raid on a bank in Greystones, Co Wicklow on Friday morning.
This is the third time this year the bank has been targeted in similar attacks.
The robbery took place at a Permanent TSB branch shortly after 4am.
It is understood the raiders used a sledgehammer to get through the front door.
The sledgehammer could be seen inside the bank later in the day along with a long plank of wood.
A Garda spokesman said it was not yet clear how much cash was stolen during the robbery.
The ATM was extensively damaged during the raid.
The scene has been preserved for a technical examination and investigations are ongoing.
Anyone with information is asked to contact Greystones Garda station (01) 6665800 or the Garda Confidential Line 1800 666 111.
In September, a gang used a car to ram the same bank in an attempted robbery. .
Earlier this year in March, there was a similar style raid about 4.20am.
A sledgehammer was also used to try and get in through the front door.