KABUL (Reuters) -- Afghan President Hamid Karzai has condemned a U.S. coalition air strike that killed 14 guards of a road construction project in eastern Afghanistan.
Karzai said last week the killing of Afghan civilians in air strikes was the biggest source of tension with his main backer, the United States, and called on President-elect Barack Obama to make it his priority to put a stop to it.
"Despite the Afghan government's constant requests to NATO and coalition forces to prevent air strikes that cause the death of innocent people and civilians, such an incident has happened once again which has no justification," a presidential palace statement quoted Karzai as saying.
But a joint statement issued by the U.S. military and Karzai's own Interior Ministry said the guards had shot at coalition forces when troops stopped their vehicles in the eastern province of Khost on November 9.
"The occupants of the vehicles got out of their vehicles and fired on the coalition forces who returned fire with rifles and helicopter gun fire," the joint statement said.
"There were secondary explosions in the vehicles, and 14 armed men were killed. Numerous ammunition belts and small-arms weapons were recovered from the vehicles," it said. 'Increases The Distance'
But Karzai called on foreign forces to do everything possible to avoid a repeat of such an incident.
"Carrying out such strikes increases the distance between the people and the Afghan government, and also between Afghanistan and its international allies," Karzai said.
The incident comes after a string of mistaken U.S. air strikes this year which have killed dozens of Afghan civilians, undermining public support for the continued presence of more than 60,000 NATO-led and U.S. coalition troops in Afghanistan.
A joint Afghan-U.S. investigation found that an air strike last week killed 37 civilians and wounded 35 after Taliban militants used the victims' village as cover for an ambush.
NATO and the U.S. military accuse the Taliban of deliberately launching attacks from within populated areas in order to provoke a response that kills civilians.
Security companies recruit hundreds of armed guards to protect construction projects, pushing up the cost of building roads paid for by international donors to close to $1 million per kilometer in the violent south and east, compared to around $200,000 a kilometer in the more peaceful north.
The guards, often recruited along tribal lines, have been accused of using their weapons to settle old scores and security experts say some of the money paid to the security companies is used to buy off the Taliban so as they do not attack.
Some 4,000 people, one-third of them civilians, have been killed in fighting this year as the Islamist Taliban steps up its campaign to topple Karzai's government and oust foreign troops.