A 25-year-old man shot dead in Limerick last week was an innocent victim of a feud between two teenage gangs.

Daniel Fitzgerald (25) was visiting his uncle Paul Fitzgerald at his cottage near Beary's Cross on the Limerick to Tipperary Road when he was shot dead as he left a caravan at the rear of the house on Tuesday night. He was not the intended target.

Tensions between two groups of teenagers in Limerick began to escalate about three weeks ago, culminating in Fitzgerald's murder. The 25-year-old was not involved in this dispute.

It is understood that a teenage member of the Collopy gang, not involved in the major feuding in the city, chased another teenager through Limerick city with a knife last weekend, which led to teenagers from the other gang setting fire to an ice-cream van that belonged to another Collopy family member. In retaliation for this, members of the Collopy gang and their associates pulled into the driveway behind the cottage near Beary's Cross and opened fire as Fitzgerald left the caravan.

It's believed they were hoping to shoot at people – distantly related to Paul Fitzgerald – who regularly visited the house. Paul Fitzgerald and his wife were not connected to the feud. Gardaí believe the gang went with the intention of shooting at the house and then murdered Daniel Fitzgerald when he came into view.

Standing inside the caravan when Fitzgerald was shot was another man holding an infant. The victim was shot in the head and the leg. The gang's getaway car, a Toyota Corolla, was later discovered partly burnt out in a field in east Limerick.

A 19-year-old man who is a leading member of the Keane-Collopy gang was arrested, along with a 38-year-old woman and two teenage girls, about an hour after the murder took place. The four, who are related, were all arrested at the same house, which is close to the scene of the fatal shooting. Three other males, aged from late teens to early 20s, were later arrested in Limerick city in connection with the murder, and a 17-year-old male was arrested in the Newcastle West area. All eight were still in custody this weekend.

A source said the row started between the two groups of teenagers and was considered an extremely low-level "tit-for-tat" dispute. The two groups of teenagers live just two miles from each other in Limerick. In retaliation for Fitzgerald's killing, a gunman opened fire at a home at Fairview Crescent, Garryowen, in Limerick city hours later. This house belongs to a member of the Collopy family who is not involved in criminality.

Daniel Fitzgerald was not known to gardaí and has been described by Superintendent Ann Marie McMahon of Roxboro Road garda station as "a very hard-working man". His parents, Noel and Teresa, travelled to Limerick from their home in Belfast after his murder and are said to be in deep shock.