KABUL (AFP) -Five crew members were killed when a US military helicopter crashed in strife-torn southeastern Afghanistan, but there were no indications hostile fire brought the chopper down, the US military said.

The cause of the crash in insurgency-hit Zabul province was unknown but there were &#34no indications of hostile fire involved at this time,&#34 it said in a statement.

The CH-47 Chinook was supporting operations in the area at the time of the crash, the military said.

US ground forces were at the scene providing security for the recovery operation, it said.

Deh Chopan has been the scene of some of the fiercest clashes between US and Afghan government forces and their opponents from the hardline Taliban regime, which was ousted in a US-led campaign in 2001.

A Taliban spokesman said he was not aware of Sunday”s crash.

Coalition forces flying missions above Afghanistan”s difficult, rugged terrain have suffered 12 helicopter crashes since the end of 2001, including Sunday”s.

The 11 previous crashes had claimed 72 lives.

In June Taliban insurgents in eastern Kunar province shot down a specially modified US Chinook, killing all 16 people aboard in the worst single attack on US forces in the country since 2001.

Three months earlier a Chinook carrying 18 people, three of them civilians, went down in an accident in bad weather in April, killing all on board.

The United States has made heavy use of air power to support ground operations by Afghan forces in the past, relying on the huge twin-rotor Chinooks which can carry up to 34 people.

The Chinooks are the mainstay troop carriers for the 20,000-strong US-led force operating in the country but are vulnerable to the difficult flying conditions in Afghanistan.

The force was a key part of massive security laid on for Afghanistan”s parliamentary election last Sunday, the first in three decades. The Taliban had warned it would disrupt the vote, but the polls passed off without major violence.

Southern and eastern Afghanistan are in the grip of an insurgency by the fundamentalist Taliban which was pushed from power after they failed to handover Osama bin Laden for the September 11, 2001, attacks on New York and Washington.

More than 1,000 people have died in political violence since the beginning of the year, most of them in clashes between suspected Taliban rebels and their opponents.

The toll, which includes more than 50 US soldiers, has made this year the bloodiest since the Taliban were removed from power.