Islamabad  - A suspected US missile strike in Pakistan's troubled North Waziristan tribal district killed at least four militants and wounded five others, an official said on Thursday.

Two missiles believed to have been fired by a US-operated Predator drone flattened a compound in the Humzoni area, located some 15 kilometers from the region's main town of Miranshah.

"The midnight [on Wednesday] attack left four militants dead," an intelligence official said on condition of anonymity. Five more suffered injuries in the explosions.

The identities of those killed were not immediately clear, according to the official.

"Our [intelligence] agents are trying to confirm if the strike targeted foreign militants or any senior al-Qaeda figure," he said.

North Waziristan is described as a haven for Taliban fighters and their al-Qaeda sponsors, who use the rugged territory to launch deadly assaults on the Western forces fighting the insurgency in Afghanistan.

The United States rarely acknowledges such drone strikes, but only its military and the Central Intelligence Agency in Afghanistan are known to operate armed reconnaissance aircraft.

Although Islamabad opposes the deployment of US drones inside Pakistani territory, these pilotless planes have killed several senior al-Qaeda and Taliban figures.

Former Pakistani Taliban leader Baitullah Mehsud died in a similar attack on August 5. (dpa)