 -- An Idaho Army National Guard helicopter crashed during a training mission Thursday, killing the two people aboard, Idaho National Guard spokesman Col. Tim Marsano confirmed.

The accident happened at 7 p.m. local time, about 2 miles south of the National Guard base at Gowen Field near Boise International Airport.

The cause of the crash is unknown, and the victims' identities have not been released.

“The men and women of the Idaho National Guard are united in grief at the loss of two of our brothers in arms, who gave their lives while training to defend our nation,” Idaho National Guard Cmdr. Maj. Gen. Gary Sayler said in a statement. “Today, our thoughts and prayers are with their families.”