KABUL ; A helicopter crash and separate collision involving two other choppers killed 14 Americans today in one of the deadliest days for US troops in the war in Afghanistan, the US military said. In the first crash, a helicopter went down in the west of the country after leaving the scene of a firefight with insurgents, killing 10 Americans - seven troops and three civilians working for the government. Eleven American troops, one US civilian and 14 Afghans were also injured. In a separate incident in the south, two other US choppers collided while in flight, killing four American troops and wounding two more, the military said. US authorities have ruled out hostile fire in the collision but have not given a cause for the other fatal crash in the west. Taliban spokesman Qari Yusuf Ahmedi claimed Taliban fighters shot down a helicopter in northwest Badghis province’s Darabam district. It was impossible to verify the claim and unclear if he was referring to the same incident. US forces also reported the death of two other American troops a day earlier: one in a bomb attack in the east, and another who died of wounds sustained in an insurgent attack in the same region. The deaths bring to at least 46 the number of US troops who have been killed this month. The deaths come as US officials debate whether to send tens of thousands more troops to the country and the Afghan government scrambles to organise a November 7 runoff election between President Hamid Karzai and challenger Abdullah Abdullah from an August vote that was sullied by massive ballot-rigging. President Barack Obama’s administration is hoping the runoff will produce a legitimate government. Another flawed election would cast doubt on the wisdom of sending more troops to support a weak government tainted by fraud. In Washington, Obama was to meet with his national security team today in what was to be the sixth full-scale Afghanistan conference in the White House Situation Room. Earlier this month, insurgents killed eight American troops in an attack on a pair of isolated US outposts in the eastern village of Kamdesh near the Pakistan border. That was the heaviest US loss of life in a single battle since July 2008, when nine American soldiers were killed in a raid on an outpost in Wanat in the same province. “These separate tragedies today underscore the risks our forces and our partners face every day,” said Colonel Wayne Shanks, a spokesman for the NATO-led coalition. “Each and every death is a tremendous loss for the family and friends of each service member and civilian. Our grief is compounded when we have such a significant loss on one day.” US military spokeswoman Elizabeth Mathias said coalition forces had launched an operation to recover the wreckage of the helicopter that was downed in the west. She said the aircraft was leaving the site of a joint operation with Afghan forces when it went down. The joint force had “searched a suspected compound believed to harbour insurgents conducting activities related to narcotics trafficking in western Afghanistan,” NATO said in a statement. “During the operation, insurgent forces engaged the joint force and more than a dozen enemy fighters were killed in the ensuing firefight.” Afghanistan is the world’s largest producer of opium - the raw ingredient in heroin - and the illicit drug trade is a major source of funding for Taliban and other insurgent groups.