The AH-64 Apache helicopters "crashed today near Healy, Alaska, returning from a training flight. First responders are on the scene. The incident is under investigation and more information about the incident will be released when it becomes available," the US Army's 11th Airborne Division said in a statement.

It wasn't immediately clear the condition of those involved in the crash.

The accident followed a similar incident in late March in which two US Army Blackhawk helicopters crashed during a training flight in Kentucky, killing all nine soldiers on board.

There have been multiple other crashes of US military aircraft in recent years, including another involving a Black Hawk that killed two Tennessee National Guardsmen during a training flight in Alabama in February.

Four US Marines were killed during NATO exercises in Norway last year when their V-22B Osprey aircraft went down, possibly after hitting a mountain, investigators said.

And two US Navy pilots were rescued after their T-45C Goshawk jet crashed during a training exercise in a residential neighborhood near Fort Worth, Texas in 2021. The pilots ejected before the plane went down.