An Afghan security official says Afghan and international troops have killed more than 70 Taleban insurgents during a week-long operation in southern Helmand province.

The official, who spoke anonymously, said five Taleban commanders are among the dead in Nahri Saraj district. He said troops have re-taken control of the area, and he added that Nahri Saraj is now "cleared" of Taleban fighters.

NATO and the U.S.-led coalition were not able to immediately confirm the Afghan official's statement.

Troubled Helmand province is a hotbed of insurgent activity. It is the hub of Afghanistan's booming illegal drug industry.

Elsewhere in the south, authorities say eight police officers were killed when a roadside bomb tore through their vehicle in Kandahar province.

Some information for this report provided by AP and AFP.