At least 17 people, including 12 Afghan army soldiers, were killed Thursday in a helicopter crash in the southern province of Zabul, officials said.
The military helicopter went down due to technical reasons in Shinkay, a district relatively free of insurgent activity in Zabul.
"Five crew and 12 soldiers were killed when the helicopter crashed in Shinkay district of Zabul province due to technical issues," a provincial police official told AFP on condition of anonymity.
Shinkay district chief Mohammad Qasim Khan confirmed the death toll, with an army commander saying an official delegation has been dispatched to the area to investigate the crash.
Aircraft crashes have been a regular risk for Afghan and foreign coalition forces, with troops relying heavily on air transport to traverse Afghanistan's rugged terrain to fight the Taliban.
The insurgents have on occasion brought down NATO helicopters, notably a US Chinook in 2011, which killed 30 Americans, but such incidents have been rare.
In April last year five British troops died when their helicopter crashed in Kandahar province in what London's Ministry of Defence said at the time appeared to be a "tragic accident".
US-led NATO forces ended their combat mission in Afghanistan in December, leaving local forces to battle militants alone, but a 13,000-strong residual force remains for training and counter-terrorism operations.