US and Afghan forces meanwhile killed four "enemy" in the south, scene of regular attacks by loyalists of the Taleban regime ousted in 2001, and a senior police officer was killed by suspected insurgents near the capital Kabul.
The seven policemen were shot in an ambush Wednesday on a highway between Uruzgan province and Kandahar, the birthplace of the Taleban, Uruzgan governor Jan Mohammad told AFP.
A man identifying himself as a spokesman for the Taleban, Qari Yousuf Ahmadi, claimed responsibility for the ambush in a telephone call to AFP.
"We ambushed the police convoy, killed a big number of them and destroyed their vehicles and seized a radio, two vehicles and weapons," he said.
In another incident in Uruzgan, Taleban insurgents abducted two civilians on Monday and beheaded them, governor Mohammad said.
The killings led to a security force sweep in which two Taleban rebels were arrested and eight motorcycles seized, the governor said.