Five people killed when a balcony collapsed during a party at an apartment in the US are believed to be Irish, local police have told Irish government officials.
Another eight people were injured when the fourth-floor balcony collapsed in central Berkeley, California, in the early hours of this morning.
Ireland's Foreign Affairs Minister Charlie Flanagan received reports from emergency services and consular officials in the US which confirmed the tragedy.
"It is with great sadness that I confirm that a number of young Irish citizens have lost their lives, while a number of others have been seriously injured following the collapse of a balcony," he said.
It is reported the balcony fell on to a footpath from the top of a four-storey building shortly after midnight local time.
Relatives of the dead and injured have been in contact with at least three hospitals in the state which responded to the emergency.
The Irish students were at a party in the apartment at a complex in Kittredge in the university city when the balcony crashed to the ground.
It is not clear whether they had been studying at the college or were in the state on J1 visas, a common summer trip for young Irish people.
There were no immediate details of how the incident occurred.
Berkeley Fire Department and police and city officials are said to be on the scene, which has been sealed off.
"My heart goes out to the families and loved ones of the deceased and those who have been injured in this appalling accident," said Mr Flanagan.
"My department in Dublin stands ready to provide all possible consular assistance to the Irish citizens affected by this tragedy."
Jennifer Coats, a spokeswoman with the Berkeley Police Department, told local media that many of the injured had suffered critical, life-threatening wounds.
"We don't have a lot of specific detail at this point because they (investigators) are still trying to work through it all," said Ms Coats.
Those caught up in the incident were rushed to hospitals and trauma centres in and around Berkeley, and also in Oakland and to Walnut Creek, with fire crews from several stations in the city involved in the emergency response.
Social workers were on hand in some of the hospitals to field calls from family and friends of those caught up in the accident.
At least four people were taken to the Sutter Alta Bates Summit Medical Centre.
A 21st birthday party was taking place in the apartment when the accident happened.
The complex at Liberty Gardens was built in 2006.
Pictures showed that the balcony appeared to have broken off from the building and partly landed on the balcony below as well as in the street.
Irish President Michael D Higgins sent a message of condolence while on a state visit to Italy.
"I have heard with the greatest sadness of the terrible loss of life of young Irish people and the critical injury of others in Berkeley, California, today," he said.
"My heart goes out to the families and loved ones of all those involved. I have been informed of the consular assistance being provided to assist all of the families involved and I have asked to be kept informed as further details emerge."
The US Ambassador to Ireland, Kevin O'Malley, expressed sympathy to the families, loved ones and friends of those who died.
"All of us at the United States Embassy are greatly saddened by news of this tragic incident and are ready to do whatever we can to assist the Irish Department of Foreign Affairs at this difficult time. We will continue to co-ordinate as more details become available," he said.
Northern Ireland Deputy First Minister Martin McGuinness added his condolences over the tragedy.
"Shocking news of the deaths of several young Irish people in a tragic accident in California. My heart & sympathy goes out to their families," he said.
Brendan Smith, foreign affairs spokesman for the Fianna Fail party, said: "I wish to extend my deepest sympathies to those who have lost a loved one in this tragic accident. The details are still emerging and it may be a number of days before we have a clear picture of what happened.
"This is an extremely difficult time for the families and my thoughts and prayers are with them."