A cargo plane crashed into mountains east of Afghanistan's capital Kabul on Tuesday, with initial reports saying all eight people aboard were killed, an Afghan airport official said.

The plane was flying from Bagram Air Field when it went down east of the capital at about 8 p.m. (1530 GMT), Kabul Airport Director Mohammad Yaqub Rassuli told The Associated Press.

Rassuli said all eight crew members were believed dead.

The aircraft was carrying supplies for NATO forces in the country, Rassuli said.

The cause of the crash wasn't immediately known. Weather conditions were clear Tuesday evening.

NATO said in a statement the crash occurred about 16 miles (30 kilometers) east of Kabul International Airport.

NATO said early reports indicated the plane was an L-100 Hercules aircraft, the civilian equivalent of a military C-130. The plane was not a NATO aircraft, the alliance said.

Afghan and NATO troops were conducting a search-and-rescue mission, the alliance said.

Bagram, which lies north of Kabul, is the main U.S. military base in Afghanistan.

In May, a passenger plane operated by Pamir Airways, a private Afghan airline, crashed while traveling from Kunduz in northern Afghanistan to the capital. All 44 passengers on the plane died.