A US military helicopter crashed during an anti-militant operation in Afghanistan Sunday killing all five American crew members, just days after President Hamid Karzai questioned the need for military operations.

The crash of the CH-47 Chinook in the southern province of Zabul came after a series of clashes between US-led forces and Taliban insurgents following September 18 legislative elections that the guerrillas failed in their vow to derail.

US military spokesman Colonel Jim Yonts said the helicopter crashed in Zabul's Dai Chophan district while returning to base after dropping off troops during an anti-militant operation.

Taliban spokesman Abdul Latif Hakimi claimed the guerrillas shot down the helicopter using "modern weapons" he did not describe, but Yonts said all indications were that hostile fire was not to blame.

"Five crew members on board were killed," Yonts said.

He said that while militant forces were in the area of the operation, the aircraft, part of a flight of helicopters involved in the mission, came down in a rugged, remote area where there was no civilian population.

"Indications are from crew members' ... reports that there was no hostile fire that caused this crash," he said, adding that a mechanical problem may have been to blame.

Until Sunday, at least 49 US troops had died this year in hostile fire, making it the bloodiest for US forces since they overthrew the Taliban in late 2001 for refusing to give up al-Qaida leader Osama bin Laden, mastermind of the September 11 attacks.

Source: China Daily