Gardaí in Dublin are investigating three separate aggravated burglaries at a social housing estate for older people.
The incidents happened on Ballygall Road East in Glasnevin within a week of each other.
At around 9pm last Friday night, a male intruder forced his way into a house in the area.
He threatened and assaulted a man in his 60s at knife point, before making off with a sum of cash.
In the early hours of Wednesday morning, the occupants of two houses in the same estate - a man in his 80s and a man in his 60s - were threatened at knife point by two male intruders, before being tied up.
The intruders escaped with sums of cash.
Gardaí are carrying out forensic examinations to see if the incidents are connected.
No arrests have been made in connection with the investigations.
