Investigations are underway after three separate aggravated burglaries at a social housing estate for older people in Glasnevin.
The incidents happened in the Ballygall Road East area.
Last Friday night, a man is said to have forced himself into a house.
He threatened and assaulted the occupant of the house - a man in his late 60s - at knife point, before making off with cash.
Shortly after midnight on Wednesday morning, meanwhile, two men - aged in their 80s and 60s - in two different houses were threatened by intruders with knives.
The male intruders escaped with sums of cash.
Forensic exams are being carried out to see if the incidents are linked, and no arrests have been made so far.
Anyone with information is being asked to contact Santry Garda Station 01-6664000.