Several casualties have been reported after two U.S. Army Blackhawk helicopters crashed during a training incident in Kentucky on Wednesday night, officials said.

“We can confirm two aircraft from the 101st were involved in an accident last night resulting in serval casualties,” the 101st Airborne Division, the only air assault division of the U.S. Army, said in a tweet early Thursday morning. “Right now our focus is on the Soldiers and their families who were involved.”

The crash took place at around 10 p.m. local time (11 p.m. ET) during a routine training mission for crews on the two HH60 Blackhawk helicopters in Trigg County, to the west of the Army base Fort Campbell, the base said in a statement early Thursday.

The release was posted just after 2 a.m. on Twitter. The 101st Airborne Division (Air Assault) is based at Fort Campbell in Kentucky. “The status of the crewmembers are unknown at this time,” the Twitter post said. 

The state police and local officials are responding to the incident.

Kentucky State Police were on the scene of the helicopter crash, along with military investigators and several other agencies. Interacting with journalists after the crash, state police said the incident unfolded in a partially wooded field area. They said a perimeter had been set up around the debris field.