The shootings happened between 1.45am and 2.15am.
In all, windows in four houses were shot in by shotgun blasts.
Two of the shootings happened in O’Malley Park and the others occurred in Prospect and Ballinacurra Weston.
Inspector Gerry McNamara of Roxboro Road garda station said a number of people, connected to some of the houses, were known to gardaí. It is believed the shootings were carried out by members of a drugs gang based in the southside of the city.
Most of drug dealing in that part of the city is controlled by the McCarthy Dundon feud gang.
It is not known if the gang were directly involved in the attacks.
Gardaí suspect that the shootings may have been a reprisal for an earlier attack near the city centre.
Windows of a basement flat in Newenham Street were smashed in.
Gardaí estimate that in excess of 25% of all gun attacks carried out in the country take place in Limerick.