At least 10 Afghan security guards were killed Thursday when Taliban militants ambushed a logistics convoy destined for NATO forces in western Afghanistan...

At least 10 Afghan security guards were killed Thursday when Taliban militants ambushed a logistics convoy destined for US-led NATO forces in western Afghanistan, a local official said.

The guards were securing the convoy when they came under attack in Bakwa district of Farah province, on the main highway connecting the west to the volatile south, said Naqibullah Farahi, a spokesman for the provincial governor.

A spokesman for Afghan police in the west of the country, Abdul Rauf Ahmadi, said police were immediately deployed to the area to hunt down the attackers.

Taliban frequently attack convoys supplying NATO troops in Afghanistan and neighboring Pakistan, as part of their 10-year insurgency against the western-backed Kabul government since US troops toppled their regime in 2001.

Meanwhile, Afghan President Hamid Karzai Thursday accused NATO-led international forces of killing seven civilians, most of them children, in an air strike in the southern province of Kandahar.

"Initial reports as stated by the district sub-governor indicate that an air strike carried out by the international forces in Siacha village in Zhari district killed seven persons including six children and injured another two young girls," a statement from the presidential palace said.

"President Karzai was saddened when he heard the news and designated a team to fully investigate the incident."

The governor of Zhari district Niaz Mohammad Sarhadi told media sources that the strike was aimed at Taliban fighters planting roadside mines in the area but missed its target and hit residential areas nearby.

A spokesman for the NATO-led International Security Assistance Force in Kabul said he was aware of reports of civilian casualties in Kandahar, adding that a joint assessment team was going to the site.

Civilian deaths have strained relations for years between NATO-led forces and the Afghan government.

There are around 140,000 US-led NATO forces in Afghanistan with foreign combat troops scheduled to withdraw by the end of 2014.