Police say they believe the blaze was started deliberately
Detectives investigating a fatal house fire in Co Fermanagh say a 27-year-old man is being held "on suspicion of murder".
Police say they believe the blaze, in which at least three people died, was started deliberately.
Police were called to an address in the Molly Road area of Derrylin at around 7.20am on Tuesday morning.
The suspect was detained at the scene and transferred to hospital for treatment before being arrested.
Detective Superintendent Jason Murphy said: "At this time we believe the fire, which has claimed at least three lives, was started deliberately.
"We are continuing to thoroughly examine the scene along with our colleagues in the Northern Ireland Fire and Rescue Service.
"Our thoughts are with family, friends, local community and all of those affected by this tragic incident.
"I would renew my appeal to anyone who was in the Molly Road/Doon Road area this morning to contact police.
"We are particularly keen to speak to anyone who was in, or travelling through Derrylin prior to the time the fire broke out at approximately 7.10am."
Firefighters from Lisnaskea and Enniskillen were called to what the fire service described as a "well-developed" blaze at a property.
The tragedy has left locals in absolute shock.
DUP leader Arlene Foster is the local representative for the area.
"It is so devastating," she said.
"My thoughts and prayers are, of course, with the family; with the community out there in Derrylin who I am sure will rally around at this very difficult time."
Additional reporting: Jack Quann