Two branches of the KBC Bank in County Dublin have been targeted in arson attacks in the space of 48 hours.
In the latest incident, a fire was started at a branch on Main Street in Swords at about 05:00 GMT on Saturday.
The front window had been smashed and the fire caused extensive damage to the ground floor, according to Irish national broadcaster RTÉ.
It follows a fire at the bank's branch in the Sandwith Street area of Dublin at about 23:25 GMT on Thursday.
Internal walls, windows and blinds suffered minor damage.
Mayor of Fingal Councillor Anthony Lavin condemned the attack.
"I'm very disappointed that this was brought on our county in the early hours of this morning.
""I just hope it doesn't affect the livelihoods of those staff that work there.
"In this day and age of financial institutions closing down branches, it's a pity to see a branch office being attacked like this."
Gardaí (Irish police) have appealed for anyone with information to contact officers.
In a statement, a KBC Bank spokesperson said : "We are aware of these incidents and we are taking additional measures to ensure the safety of our people and the hubs that our local customers rely upon.
"As these incidents are the subject of a criminal investigation by An Garda Síochána we are not in a position to provide further comment at this time."