At least three people have died following an explosion at a petrol station in Co Donegal.
It happened in apartments above a shop at around 3:20pm on Friday in Creeslough.
It is unknown how many people have been injured.
An Garda Síochána say they are continuing to assist other emergency services at the scene of the "serious ongoing incident".
The other agencies involved include the Irish Coast Guard, the Coast Guard Rescue 118 helicopter, Irish Air Corps Medivac 112, Donegal Mountain Rescue, the Donegal County Council Civil Defence and Northern Ireland Ambulance.
Gardaí say further information on casualties is not available.
People intending to travel to the Creeslough area are being advised to use alternative routes.
My thoughts and prayers are tonight with the entire community of Creeslough following today’s devastating explosion.
Thinking too of all the emergency services, from across the north-west and NI working in very traumatic situation.
— Micheál Martin (@MichealMartinTD) October 7, 2022
Taoiseach Micheál Martin said: "My thoughts and prayers are today with those who have lost their lives, and those injured in the devastating explosion in Creeslough.
"I wish to express my deepest sympathies to their family, and friends, and to the entire community of Creeslough, on this darkest of days for Donegal and the entire country," he said.
"People across this island will be numbed by the same sense of shock and utter devastation as the people of Creeslough at this tragic loss of life.
"I would like to thank all the members of the emergency services, from across the north-west and Northern Ireland, who responded so quickly to the scene, and who are working throughout the night in extremely traumatic circumstances."
Tánaiste Leo Varadkar said: "Our thoughts are with all those affected by the tragic events and with the emergency services responding."
While Sinn Fein TD for Donegal Pearse Doherty said it was 'devastating news'.
Letterkenny University Hospital earlier confirmed there were "multiple injured people requiring immediate attention".
The hospital said it had moved to 'Major Emergency Standby' as it dealt with the incident - however this has since been stood down.
In an earlier statement, Applegreen said: "The thoughts and prayers of everyone here at Applegreen are with all of those who have been affected."