Ten people from two families, including a mother, father and a five-month-old baby, have been killed in a fire.
Five children under 10 are believed to be among the dead after the blaze broke out at a halting site for travellers in Carrickmines, south Dublin, at about 4am.
The families are understood to have been living at the encampment off the Glenamuck Road, just south of the M50 motorway and a few miles from Sandyford village, for about eight years.
The fire is being treated as a tragic accident, a traveller support group said.
A Garda spokesman confirmed the death toll had climbed to 10 after the baby girl, understood to have turned five months at the end of September, died in hospital.
The Southside Traveller Action Group, which knew some of those involved, offered its deepest sympathies to the relatives of the families.
A spokeswoman said staff were in a state of shock at the devastating loss of lives.
"Families gathered today at our centre in southside Dublin where we are doing everything we can to support them. We thank the gardai for their support at this time and appeal to the media to respect the privacy of the families of those who died," the group said.
The halting site was described as four bay and is understood to have contained a number of caravans.
The alarm was raised at 4.24am with six units of the Dublin Fire Brigade on the scene and a number of paramedics and ambulances.
Gardai are investigating the cause of the blaze but early indications are that it was not a criminal act and it is not being treated as suspicious.
Emergency services said two adults and two children were taken from the scene to hospital while a number of others were confirmed dead at the halting site.
It is understood the scene was difficult to examine due to the extensive damage caused by the blaze and the number of people caught up in it.
Forensic examinations were continuing late into the evening with Dr Margaret Bolster, assistant state pathologist, at the halting site leading the technical analysis.
President Michael D Higgins said he was shocked and saddened at the deaths.
"My thoughts at this time are with the families and friends of those who have lost their lives and those who have been injured," he said.
"I have asked to be kept informed on this shocking event throughout the day."
The Archbishop of Dublin, Diarmuid Martin, said the incident was heartbreaking for all in the traveller and wider local community, and asked for prayers to be said for the dead and injured and their families.
Alan Kelly, Environment Minister, issued a statement on behalf of the Government and said he learned of the tragedy with shock and the deepest regret.
"On behalf of the Government I want to extend our prayers and deepest sympathy to the families of the deceased and their extended community," he said.
Fianna Fail leader Micheal Martin said: "This is an extremely shocking incident and I want to express my deepest sympathy to the families affected by this tragedy."
Sinn Fein president Gerry Adams said it was "horrific news to wake to on a Saturday morning".
Alex White, Minister for Communications, Energy and Natural Resources and TD for Dublin Rathdown, said: "Our thoughts and prayers are with those who are currently battling with their injuries, and the families and friends of all those who died."