Islamabad: At least five suspected militants were killed and several others injured when a US drone targeted a vehicle in the restive South Waziristan tribal region of Pakistan on Monday.

The CIA-operated drone carried out the attack in Birmal area of South Waziristan Agency, TV news channels quoted officials as saying.

The unmanned plane fired two missiles at the vehicle, destroying it.

The exact identity of the five men killed in the attack could not immediately be ascertained.

The US has continued its controversial drone campaign in Pakistan's tribal belt despite strong protests from Islamabad, which says the attacks are counter-productive for the war on terrorism and alienate tribesmen.