A mountain firefighting operation in northern Idaho descended into chaos on Sunday after emergency crews were ambushed by sniper fire, leaving at least two dead in what the state governor has condemned as a “heinous” attack.

Fire crews had been responding to a wildfire on Canfield Mountain, just north of the city of Coeur d’Alene, when gunshots rang out at around 2pm – roughly 30 minutes after their arrival. The Kootenai County Sheriff’s Office confirmed that gunfire continued to erupt for hours, trapping personnel on the mountain and severely hampering firefighting efforts.

Sheriff Bob Norris said the two confirmed fatalities are believed to be members of the fire response team. He was unable to confirm whether others had been injured, noting that crews were still coming down from the mountain late Sunday afternoon.

“We don’t know how many suspects are up there, and we don’t know how many casualties there are,” Norris stated during a press briefing at 4:30pm. “We are actively taking sniper fire as we speak.”

The sheriff added that the gunman – or potentially multiple assailants – appeared to be concealed within the mountain’s rugged terrain, likely using a high-powered rifle. Deputies had been authorised to return fire in the hopes of neutralising the threat.

“I’m hoping someone has a clear shot,” Norris said, “because they’re not showing any signs of surrender.”

Idaho Governor Brad Little called the attack a deliberate and despicable act, targeting those risking their lives to protect others.

“This is a heinous direct assault on our brave firefighters,” the governor posted on social media platform X. “I ask all Idahoans to pray for them and their families as we await further information.”

The Kootenai County Emergency Management Office has issued a public alert urging people to avoid the Canfield Mountain Trailhead and nearby Nettleton Gulch Road, located about four miles north of Coeur d’Alene’s city centre.

With the area still considered unsafe, Sheriff Norris confirmed that the wildfire continues to burn unchecked. “We can’t put any resources on it right now,” he said.

Canfield Mountain, known for its dense forest and popular hiking and biking trails, lies on the outskirts of Coeur d’Alene – a city of roughly 55,000 near the Washington state border.