Pakistani officials say a pair of U.S. missile strikes has killed at least 20 suspected militants in Pakistan's tribal region of North Waziristan.

Intelligence officials say the missiles were fired from drones within minutes of each other Wednesday, with two of them hitting a vehicle and the other two a nearby compound. The strike took place in the village of Zoynarai in the Shawal area in the mountainous region close to the border with Afghanistan.

The identity of the those killed was not immediately known. But the Haqqani network and foreign militants are known to operate in the region, as well as a Pakistani warlord, Hafiz Gul Bahadur, who is involved in the fight against Western forces in Afghanistan.

Wednesday's strikes came two days after U.S. missiles killed 18 militants in nearby South Waziristan. The United States has said the semi-autonomous region of northwest Pakistan is the headquarters of al-Qaida and Taliban militants leading the fight against the U.S. and its allies in Afghanistan.

The United States does not officially confirm the Predator drone strikes, which are hugely unpopular among Pakistanis. But the CIA and the U.S. military are the only forces deploying the unmanned aircraft in the region. U.S. officials say the missile strikes have severely weakened al-Qaida's leadership.

The Pakistani parliament approved a resolution demanding the end of the missile strikes, but the U.S. has ignored it.