A US drone strike targeting a militant compound in Pakistan's northwestern tribal district killed at least five militants late Tuesday, security officials said.

The unmanned aircraft fired two missiles on the compound in the Shawal area, some 50 kilometres southwest of Miranshah, the main town of North Waziristan tribal district, near the Afghan border.

The area is considered to be a hub of Taliban and Al-Qaeda activity.

"At least five militants have been killed and three have been wounded. The compound was completely destroyed," a senior security official based in Peshawar city told AFP.

All those killed were fighters linked with local warlord Hafiz Gul Bahadur, another security official based in Miranshah told AFP.

Bahadur, who is allied with Afghan Taliban, is accused of fighting US-led troops across the border.

He last week imposed a ban on anti-polio vaccination teams in protest at US drone strikes, officials said.

Local officials told AFP on Tuesday that they had so far failed to convince him to allow the vaccinations.

Bahadur said the ban would remain until the US stops drone attacks in the tribal region.

But Washington considers Pakistan's semi-autonomous northwestern tribal belt the main hub of Taliban and Al-Qaeda militants plotting attacks on the West and in Afghanistan.

Islamabad is understood to have approved the strikes on Al-Qaeda and Taliban targets in the past. But the government has become increasingly energetic in its public opposition as relations with Washington have nosedived.

US officials consider the attacks a vital weapon in the war against Islamist extremists, despite concerns from rights activists over civilian casualties.

The London-based Bureau of Investigative Journalism has said that under President Barack Obama one drone strike has hit Pakistan on average every four days.

It said most of the 2,292 to 2,863 people reported to have died were low-ranking militants, but that only 126 fighters had been named.

It said it had credible reports of between 385 and 775 civilians being killed, including 164 to 168 children.