http://en.wikipedia.org/wiki/File:Road_from_Jalalabad_to_Kabul.jpg Nine young girls were killed in eastern Afghanistan on Monday when they stumbled across a buried Taliban bomb as they collected firewood, according to local officials.

The blast happened in the eastern province of Nangarhar, which borders Pakistan, and has been the scene of frequent insurgent activity.

All the girls killed were aged nine to 13. Two other girls were taken to hospital with serious injuries.

Investigators unearthed two more hidden bombs after reaching the scene, according to a spokesman for the provincial governor.

Ahmad Zia Abdulzai said a tenth girl, who had been presumed dead but was found hours after the explosion, had described what happened.

"One of the girls had found something buried and shouted 'Come, come see what I've found,'" to the others," he said. "One of them must have done something to trigger it."

He added that security forces believed that the Taliban had hidden the explosives and planned to return under cover of darkness to move them to a target – possibly a road.

"This is a very sad day for our province and for Afghanistan," he said. "We will work to find the elements responsible." The bodies were so badly disfigured they would be difficult to identify, he added.

President Hamid Karzai condemned the blast as "an unforgivable crime" in a statement. Civilians are frequent victims of discarded or hidden explosives.

Thousands of mines date back to the Soviet occupation of Afghanistan, which ended in 1989. Thousands more were planted in the years of civil war that followed.

In the first six months of 2012, 1,145 Afghan civilians were killed and around 2,000 wounded, mostly by roadside bombs Elsewhere, a Taliban car bomb killed one person and wounded at least 15 when a car bomb was detonated outside the office of an American contracting company in the Kabul.

It is the latest reminder that security remains fragile in the capital as international forces withdraw troops ahead of a 2014 deadline.

Police said three foreigners were slightly injured in the attack on Contrack, a company that builds bases for the Afghan army and police.

The Taliban claimed responsibility, accusing the company of providing security to the "invading forces".

"This company was under the surveillance of the Mujahideen for a while and thanks God today the opportunity was provided to attack it," said the movement's spokesman, Zabibullah Mujahid, in a statement.