Taliban-linked rebels beheaded six Afghan policemen after overrunning their checkpoint during clashes in northern Afghanistan, NATO said today.

The incident took place yesterday in the province of Baghlan, a region where insurgents have gained strong footholds in recent years, NATO's International Security Assistance Force (ISAF) said.

The military said police "successfully repelled" an insurgent attack on a school, clinic and the district governor's building in Dahanah-ye Ghori, killing several insurgents.

But added: "During the attack, insurgents overran a police checkpoint and killed the police officers by cutting off their heads."

ISAF condemned the "brutal" killings.

Abdul Majeed, provincial governor confirmed that six Afghan policemen had been killed in their post but refused to give details.

Deaths among Afghan and foreign security forces have surged in recent months as NATO, US and Afghan troops roll out a counter-insurgency strategy designed to reverse the Taliban momentum and speed an end to a nearly nine-year war.