By Maqsood Amarkhil
A US airstrike has killed up to 10 Afghan soldiers Monday (local time) at an army checkpoint in a Taliban-infested province south of Kabul, one of the deadliest episodes of "friendly fire" from foreign forces in recent years.
The early morning raid in Baraki Barak district of Logar province comes as coalition forces increase air strikes on potential militant targets despite a drawdown of NATO forces after 13 years of war.
The bombing marked the second such incident in the area since last December when a NATO air strike killed five civilians and wounded six others.
"At 6am today, two US helicopters attacked a checkpoint in Baraki Barak," district governor Mohammad Rahim Amin told AFP.
"The checkpoint caught fire... and 10 Afghan army soldiers were killed," he added, revising down his earlier toll of 14.
Civilian and military deaths in coalition airstrikes have been one of the most emotive and high-profile issues of the war, often provoking fury from the government.
An American military official said he was "aware of an incident involving US forces in Logar province this morning".
"This incident is under investigation," he added.
Logar's deputy police chief, Mohammad Wara, also said 10 Afghan soldiers were killed and four others were wounded but provincial army commander, Abdul Razid Safi, said the attack resulted in eight fatalities.
Amin said the targeted outpost was "not a suspicious area".
"The Afghan flag was waving at the checkpoint in Baraki Barak when the Americans launched their attack," he said.
But the Afghan defence ministry said "armed insurgents had opened fire on the coalition forces' helicopters", though it did not say if that had prompted the friendly fire.
Following the attack, an Afghan army convoy dispatched to the site was ambushed several times on its way by Taliban militants, but they managed to retrieve the dead bodies without any further casualties, Amin said.
US-led NATO forces ended their combat mission in Afghanistan in December, leaving local forces to battle the Taliban alone, but a residual force remains for training and counter-terrorism operations.
Despite the drawdown, the US carried out 106 military air strikes in June, a sharp jump compared to the previous month when it carried out 41 strikes.
While "friendly fire" incidents involving foreign coalition forces are a deeply contentious issue in Afghanistan, UN statistics show that the Taliban are responsible for most deaths.