Suspected US drones fired missiles into a Pakistani tribal region on Friday, killing 12 people, including five foreigners, in an area known as a stronghold of Pakistani Taliban commander Baitullah Mehsud.

Pakistani officials said the attack targeted a house in a remote village on the border between North and South Waziristan, where Mehsud, an al Qaeda ally, has been bottled up by Pakistani forces since early this year.

Frustrated by fighters from Pakistan fuelling the Taliban insurgency in Afghanistan and fearful of al Qaeda regrouping, U.S. forces have intensified missile attacks by pilotless drones since early September, security sources say.

"We have reports that 12 people were killed, including five foreigners," a paramilitary official told Reuters by telephone from the area.

It was unclear if the dead foreigners included Arabs, who usually signify an al Qaeda presence.

A relative and aides to Mehsud, and Pakistani government and paramilitary officials said the attack happened at around 1:45 a.m. (2045 GMT), and up to four missiles were fired.

"There were two drones flying in our area and they fired four missiles," a paramilitary official in the area said. "They were American."

Missile-armed drones are primarily used by US forces in the region, though the United States seldom confirms drone attacks. Pakistan does not have any.

Mehsud, who was accused of being behind the assassination of former prime minister Benazir Bhutto last December, married a second wife in a ceremony held earlier this week in the Makeen area of South Waziristan.

"Around 50 guests attended the marriage. They were all his close friends. It was a simple ceremony," close aide Mufti Wali-ur-Rehman told Reuters.

His new wife is a madrasa-schooled daughter of a cleric from his own Mehsud tribe. Mehsud has no children by his first wife. Under Islamic custom a man can take up to four wives.

CIA director Michael Hayden told a Washington think tank on Thursday that US pressure in Pakistan's borderlands aimed to put al Qaeda "off balance," and said the region represented the greatest terrorism threat to the United States.

Hayden said several al Qaeda veterans had been eliminated "by violence or natural causes" in the past year and the hunt for Osama bin Laden was "at the top of CIA's priority list."

The spy chief did not refer openly to the missile strikes or a U.S. commando raid in South Waziristan on September 3, which marked the first time the lid has been raised on the use of ground forces on Pakistan soil.

Pakistan has condemned the violations of its territory. Islamabad argues the attacks fuel anger toward the United States and undermine the government's own efforts to garner people's support for the campaign against militancy.

There are hopes in Pakistan the incoming administration of Barack Obama will be less aggressive than the outgoing George W. Bush administration in its approach to counter-terrorism operations inside Pakistan.

"It's undermining my sovereignty and it's not helping win the ... hearts and minds of people," president Asif Ali Zardari told CBS News in an interview aired overnight.

Zardari, whose 8-month-old civilian government is desperate for financial support to avert an economic meltdown, denied media speculation Pakistan had silently agreed a deal with the United States to allow missile strikes, and said more co-operation was needed.

Army chief General Ashfaq Kayani is visiting Brussels next week where he will raise the issue of the strikes and their repercussions during talks with Nato officials, according to Pakistani military sources.

The latest attack coincided with a visit by the commander of Nato-led forces in Afghanistan to Islamabad.-Reuters