Kandahar-Suspected Taliban rebelsambushed a convoy of trucks carrying supplies to a U.S.base in central Afghanistan, killing three Afghan policemen guarding it, officials said Sunday.

Rebels also attacked a police checkpoint on the main road from the southern city of Kandahar to the capital, Kabul, on Saturday,

triggering a two hour gunbattle that left one officer dead and two wounded, said local police chief Ghulan Nabi.

Some insurgents were also believed killed in the fighting, but it was unclear how many because the rebels took the bodies with them when they fled, he was quoted as saying by The Associated Press.

The attack on the supply convoy occurred in Zabul province”s Shahjoy district also on Saturday, said local government chief Rozi Khan. He said the trucks returned to the nearby city of Qalat after the fighting.