A NATO helicopter has crashed in southern Afghanistan, killing six members of the international military force, the U.S.-led coalition said Friday.
Sources in Afghanistan and Washington tell CBS News it was a U.S. Marine CH-53 helicopter that crashed, and a U.S. military official tells the Associated Press that all those killed were Marines, but the coalition has not officially disclosed the nationalities of the victims. Details of such incidents are generally kept private until the families of the dead are notified.
CBS News is still seeking independent confirmation on the nationalities of the crash victims.
The cause is still being investigated, but a coalition statement said there was no enemy activity in the area at the time of Thursday's crash, which brought the number of international forces killed in Afghanistan this month to 24.
CBS News correspondent Mandy Clark reports that some military sources are pointing to a likely mechanical failure, but they say it's too early to determine exactly what brought the helicopter down in the Taliban-dominated area.
The Taliban claimed responsibility for bringing the helicopter down in a statement to CBS News, but Clark says the militant group often exaggerates claims of military success.
The helicopter crash occurred on the same day that a rogue Afghan soldier opened fire on French troops in the country on a training mission, killing four and leading French President Nicolas Sarkozy to immediately halt all training operations in Afghanistan. He also said he may consider pulling all French troops out of the country sooner than planned.
Meanwhile, a suicide car bomber killed at least seven civilians outside a crowded gate at Kandahar Air Field, a sprawling base for U.S. and NATO operations in the south. The Taliban insurgents claimed responsibility, saying they were targeting a NATO convoy.
It was the second suicide bombing in as many days in southern Afghanistan, officials said. The coalition said no NATO troops were killed Thursday. It does not disclose information about wounded troops.
The Taliban have been stepping up attacks in southern Afghanistan, the birthplace of the insurgency, with a wave of bombings and the assassinations of three local Afghan officials this week. The violence comes even as the U.S. is moving ahead with plans for negotiating with the Taliban to try to end the 10-year-old war in Afghanistan.
Two witnesses told The Associated Press that they suspect Thursday's suicide car bomber was trying to hit U.S. troops because he detonated his explosives just as two pickup trucks, which they say are often used by American special forces, were leaving the base.
Taliban spokesman Qari Yousef said that NATO forces opened fire after the bombing and that they killed three of the seven civilians who died. The coalition denied this, saying there was no fighting after the blast.
Earlier, officials reported that the suicide bomber was walking near the gate, but the Afghan Ministry of Interior later said the attacker was driving a Toyota Corolla.
Zalmai Ayubi, the spokesman for the Kandahar provincial governor, said two children were among the seven civilians killed. He said eight other civilians, including two children and one woman, were injured in the explosion.