Helicopter crashes killed 14 Americans on Monday _ 11 troops and three drug agents _ in the deadliest day for the US mission in Afghanistan in more than four years. The deaths came as President Barack Obama prepared to meet his national security team for a sixth full-scale conference on the future of the troubled war. In the deadliest crash, a helicopter went down in the west of the country after leaving the scene of a firefight, killing 10 Americans _ seven troops and three Drug Enforcement Administration agents. Eleven American troops, one US civilian and 14 Afghans were also injured.
In a separate incident, two US Marine helicopters _ one UH-1 and an AH-1 Cobra _ collided in flight before sunrise over the southern province of Helmand, killing four American troops and wounding two more, Marine spokesman Maj Bill Pelletier said. It was the heaviest single-day loss of life since June 28, 2005, when 16 US troops on a special forces helicopter died when their MH-47 Chinook helicopter was shot down by insurgents. The casualties also mark the first DEA deaths in Afghanistan since it began operations there in 2005.
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.
Military spokeswoman Elizabeth Mathias said hostile fire was unlikely because the troops were not receiving fire when the helicopter took off.
NATO said the helicopter was returning from a joint operation that targeted insurgents involved in "narcotics trafficking in western Afghanistan."
"During the operation, insurgent forces engaged the joint force and more than a dozen enemy fighters were killed in the ensuing firefight," a NATO statement said.
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 insurgent groups.
US forces also reported the death of two other American service members 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 service members who have been killed in October.
This has been the deadliest year for international and US forces since the 2001 invasion to oust the Taliban. Fighting spiked around the presidential vote in August, and 51 US soldiers died that month _ the deadliest for American forces in the eight-year war.