US soldier killed

Meanwhile, the Nato-led International Security Assistance Force (Isaf) said one of its soldiers was killed after an attack in eastern Afghanistan on Sunday.

The separate US-led military force said the soldier was a US national.

He was killed in the town of Bargi Matal in Nuristan province, a US military spokesman said.

Afghan security forces regained control of the town on Sunday, three days after the Taliban seized it in an attack.

The Afghan defence ministry said the bodies of four fighters had been found after the military pushed back the Taliban from the mountainous region.

"In a rapid operation, the Afghan national army along with other security forces recaptured the Bargi Matal district on Sunday," AFP cited a ministry statement as saying. 

"A search and clean-up operation continues around the district," it said.