Dozens of students watched in horror as a teenage schoolgirl was stabbed during an assault by three pyjama-clad female attackers outside a rural Irish school.

The brutal assault took place in Doon, Co Limerick, on Tuesday as the 15-year-old schoolgirl was waiting to board her bus home.

Gardai are investigating the possibility that the attack was linked to a previous incident at a school dance.

As hundreds of secondary school students waited for buses and lifts home at Monastery Road at 3.30pm, a gold-coloured SUV pulled up and three women -- all wearing pyjamas -- jumped out.

They singled out the teenage girl, kicking and punching her, before stabbing her in the lower back in front of the students.

The victim fell to the ground and the assailants fled in their vehicle. She received medical treatment at the scene before an ambulance arrived and brought her to the Mid-Western Regional Hospital in Limerick.

Officers at Bruff garda station are investigating and have since interviewed a number of witnesses to the assault.

Gardai yesterday arrested three young women in the nearby village of Murroe. Two are in their early 20s, while the other is under 18 years old. All were detained under Section 4 of the Criminal Justice Act and questioned by detectives at Bruff garda station.

The three individuals were released without charge last night. A file on the matter is being prepared for the Director of Public Prosecutions.

An SUV, which officers believe the assailants used, was seized for further examination. The weapon used in the attack has not been located.

It is understood the suspects are originally from the north of Limerick city.

The victim was interviewed by gardai on Tuesday night and discharged from hospital a short time later.

She was yesterday recovering from the ordeal at her home along the Limerick-Tipperary border. It is believed the attack is linked to an ongoing dispute that included an incident at a secondary school dance. Tuesday's stabbing is not being treated as a random assault.

Local councillor Noel Gleeson (FF) said he could not believe it when he heard of the stabbing.

"It is not a thing that you associate with Doon or any of the neighbouring parishes in east Limerick," Mr Gleeson said.

"I'm disgusted that something like this could happen to a young girl who is still going to secondary school. It is an awful thing to happen to any child and I urge anyone who knows anything about it to contact the gardai immediately," Mr Gleeson said.