“This is a heinous direct assault on our brave firefighters,” said the governor. “I ask all Idahoans to pray for them and their families as we wait to learn more.”
He added: “As this situation is still developing, please stay clear from the area to allow law enforcement and firefighters to do their jobs.”
Sheriff Norris told a news conference that “we don’t know if there’s one, two, three or four” shooters at the scene, about four miles (6.5km) north of central Coeur d’Alene.
“We don’t know how many suspects are up there, and we don’t know how many casualties there are,” he added.
He said there were other people on Canfield Mountain, including hikers, so it “would be safe to assume” others are still up there.
Sheriff Norris said the call about the brush fire came in around 13:22 local time (19:22 GMT) on Sunday. He said at 14:00, firefighters reported shots fired.
He said the suspect or suspects showed “no sign of wanting to surrender”. He told reporters he hoped law enforcement could “neutralise” the assailants.
Kootenai County Emergency Management Office sent an alert asking people to avoid the area around Canfield Mountain Trailhead and Nettleton Gulch Road.