(Update: A U.S. official says three Drug Enforcement Administration agents were killed Monday when a U.S. military helicopter went down in the west of Afghanistan. The casualties mark the first DEA deaths in Afghanistan since the drug agency began operations there in 2005. The official spoke on condition of anonymity because no formal announcement has been made. Seven U.S. service members were also killed in the crash in the west of the country.)
Kabul (AP) - A helicopter crash and separate collision involving two other choppers killed 14 Americans on Monday in one of the deadliest days for U.S. troops in the war in Afghanistan, the U.S. 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 U.S. civilian and 14 Afghans were also injured.
In a separate incident in the south, two other U.S. choppers collided while in flight, killing four American troops and wounding two more, the military said.
U.S. 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.
U.S. 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 U.S. troops who have been killed in October.
The deaths come as U.S. officials debate whether to send tens of thousands more troops to the country and the Afghan government scrambles to organize a Nov. 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 Monday in what was to be the sixth full-scale Afghanistan conference in the White House Situation Room.
Also Monday, Abdullah called for election commission chairman Azizullah Lodin to be replaced within five days, saying he has "no credibility."
Lodin has denied accusations he is biased in favor of Karzai, and the election commission's spokesman has already said Lodin cannot be replaced by either side.
Abdullah made the demand in a news conference during which he spelled out a list of what he said were "minimum conditions" for holding a fair second round of voting, including the firing of any workers implicated in fraud and the suspension of several ministers he said had campaigned for Karzai in the first round before the official campaigning period began.
Abdullah did not say what would happen if his demands were not met. "I reserve my reaction if we are faced with that unfortunate situation," he said.
This has been the deadliest year for international and U.S. forces since the 2001 invasion to oust the Taliban. Fighting spiked around the presidential vote in August, and 51 U.S. soldiers died that month -- the deadliest for American forces in the eight-year war.
Earlier this month, insurgents killed eight American troops in an attack on a pair of isolated U.S. outposts in the eastern village of Kamdesh near the Pakistan border. That was the heaviest U.S. 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," Col. Wayne Shanks, a spokesman for the NATO-led coalition, said Monday. "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."
U.S. 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 harbor 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.
Elsewhere Monday, Nangarhar province Gov. Gul Agha Sherzai survived an assassination attempt after a gunman fired automatic weapons at his convoy in Jalalabad, according to his spokesman Ahmad Zia Abdulzai. Sherzai's bodyguards killed the gunman, as well as another attacker wearing a suicide vest and carrying grenades.
Meanwhile, security forces in Kabul fired automatic rifles into the air for a second day Monday to contain hundreds of stone-throwing university students angered over the alleged desecration of Islam's holy book, the Quran, by U.S. troops during an operation two weeks ago in Wardak province. Fire trucks were also brought in to push back protesters with water cannons. Police said several officers were injured in the mayhem.
U.S. and Afghan authorities have denied any such desecration and insist that the Taliban are spreading the rumor to stir up public anger. The rumor has sparked similar protests in Wardak and Khost provinces.
Associated Press Writers Rahim Faiez, Todd Pitman and Robert H. Reid contributed to this report from Kabul; Noor Khan reported from Kandahar.
The U.S. military says 14 Americans have been killed in a series of helicopter crashes in Afghanistan, but hostile fire is not suspected.