Gardai are probing if a teenager in a serious condition in hospital was struck in the head with a weapon.
The boy (17) was taken to hospital following an assault in the Clondalkin area in the early hours of yesterday morning.
It is understood that gardai believe a blunt instrument, such as a baseball bat or a wooden pole, may have been used in the attack.
The incident took place at around 1am outside a house at Rowlagh Gardens, with a number of people involved.
The teen initially returned home following the assault. However, he later felt unwell and was rushed to Tallaght Hospital by Dublin Fire Brigade.
He was then transferred to Beaumont Hospital with head injuries and is believed to be in a serious condition.
"It is understood the youth sustained head injuries during an incident involving a number of persons on the street outside a house at Rowlagh Gardens at around 1am," a garda spokesman said.
"Following the incident, the young man returned home, only for his condition to worsen.
"Emergency services were contacted and he was taken by ambulance to hospital."
Gardai were not initially called to the scene of the incident and are now appealing for anyone with information to get in touch with them.
They are particularly appealing for anyone who may have witnessed anything at Rowlagh Gardens between 1am and 2am to contact the incident room at Lucan Garda Station on (01) 6667300, or the Garda Confidential line on 1800 666 111.