BAGRAM, Afghanistan (AP) (AP) _ A U.S. Air Force helicopter crashed in southeast Afghanistan Sunday, killing all six people on board, the military said.

The HH-60G Pave Hawk helicopter was on a medical evacuation mission when it crashed shortly before 9 p.m. about 18 miles north of Ghazni, Afghanistan.

``I regret to tell you that all six aboard were confirmed dead,'' said Master Sgt. Richard Breach, a spokesman at Bagram Air Base, north of the capital, Kabul.

He said the crash was not the result of enemy action but the cause is still under investigation. The weather across Afghanistan was poor at the time, and several other flights were grounded, he said.

``Coalition forces are en route to the crash site at this time,'' Breach said.

U.S. military officials in Washington and Afghanistan said the medical emergency and the helicopter flight was not in connection with Operation Valiant Strike, a mission involving members of the Army's 82nd Airborne Division in southeastern Afghanistan.

That mission, which began earlier this month, is meant to root out remnants of the al-Qaida and Taliban believed to be operating in the area.

The last helicopter crash in Afghanistan was Jan. 30, when an Army Black Hawk helicopter _ the Army's version of the Pave Hawk _ on a training mission crashed near the Bagram air base, killing four.