Gardai in Dublin's north inner city are investigating two separate shooting incidents.
In the first, on Tuesday night, two masked men forced their way into an apartment in Buckingham Village, Buckingham Street, by pretending to be security men.
A woman opened the door and the men pushed past her. They shot the male occupant of the apartment twice with a shotgun and fled. The man, whose name has not been released, was taken to the Mater Hospital. His injuries were said to be serious, but not life-threatening.
In the second incident in the early hours of yesterday morning, two men, who were also masked, knocked on the window of a flat in Poplar Row, Ballybough. When a male occupant went to investigate the two men tried to push past him. A scuffle took place, but when another man appeared at the top of the stairs one of the two masked men fired shots from a pistol.
The second man barricaded himself into a bedroom until the two men left. One of the occupants was injured when he was struck with the pistol.
Gardai believe the attacks are unrelated.