Two firefighters were shot dead and a third wounded on an Idaho mountain when they were ambushed by a man who set the fire to lure them to the area, the local sheriff says.

The gunman suspected of fatally ambushing firefighters responding to a blaze in Coeur d'Alene, Idaho, on Sunday has been identified as a 20-year-old man who once wanted to be a firefighter, according to law enforcement officials.

Authorities said firefighters were attacked by a sniper on an Idaho mountainside while they were responding to a blaze in the northern part of the state.