A second person is being questioned by gardaí investigating the petrol-bombing of a house in Waterford last week which left three children injured.
The 17-year-old was arrested in Waterford city yesterday as part of an ongoing major investigation into the incident at the Ardmore Park estate in Ballybeg on the edge of the city.
An 11-year-old girl, Roisin Halligan, suffered serious burn injuries when she tried to protect her cousin, one-year-old Lexie Halligan, from the explosion which happened after a petrol bomb was thrown through the sitting-room window of their grandmother's house.
Roisin underwent surgery at Cork University Hospital following the attack and is expected to be in hospital for some time.
Lexie Halligan was treated for burn injuries at University Hospital Waterford while a three-month old baby, William Halligan, who was also in the house at the time, suffered smoke inhalation.
Both have since been discharged.
Their grandmother Nellie Halligan, who prevented the injuries from being worse by putting out the fire with an extinguisher, remains "very shaken" by the events of Thursday night.
Another grand-daughter, Rebecca, said Mrs Halligan has spent a lot of time in Cork hospital with Roisin and Roisin’s mother Sabrina.
The 11-year-old is expected to be in hospital for up to 12 weeks as a result of the burn injuries she sustained to her face, legs, arms, neck and back.
"She was badly, badly burnt," Rebecca Halligan said today. "The treatment is going grand but they're very concerned at her leg and her arm."
The first arrest made in relation to the incident resulted in 23-year-old Gregory Hennessy of Priory Lawn in Waterford appearing before a special sitting of the local district court on Saturday.
He was remanded in custody and is due back in court this Tuesday.
The 17-year-old arrested on Sunday was being detained on Monday under section 30 of the Offences Against the State Act. He is expected to be questioned until Tuesday morning.
There were no further incidents reported in the Ballybeg area over the weekend although a garda involved in the investigation said the situation is “volatile enough” following the petrol-bomb attack.
“We’re trying to police it as much as we can,” he said.