The Afghan government said an investigation has found that 140 civilians were killed in an incident involving U.S. airstrikes in western Afghanistan earlier this month.

The Afghan Defense Ministry announced the official death toll Saturday, making it one of the deadliest incidents for civilians since U.S. forces began fighting the Taliban in 2001.  Afghan officials said the majority of those killed were children.

The U.S military has said a "number" of civilians were killed during fighting with Taliban militants in the Bala Buluk district of Farah province May 3.  The military said the exact toll cannot be determined because all the bodies were buried before investigators arrived.

The U.S. military has also accused the Taliban of using civilians as "human shields."  It has launched its own investigation into the incident.

Afghan President Hamid Karzai has demanded an end to U.S. airstrikes.

Separately, the U.S. military said four U.S. contractors fired on an approaching civilian vehicle in Kabul earlier this month, wounding at least two Afghans.  The contractors worked for the private security company formerly known as Blackwater, which was involved in a 2007 shooting in Baghdad that killed at least 17 Iraqi civilians.

The military said the contractors were involved in a vehicle accident on May 5, and then fired on an approaching vehicle they believed to be a threat.  Their company, now known as Xe, said it has terminated their contracts and ordered them not to leave Afghanistan without the approval of the U.S. Department of Defense.

Some information for this report was provided by AFP, AP and Reuters.