Two US drone strikes targeting a militant compound and a vehicle in Pakistan's lawless tribal district of North Waziristan killed at least nine people on Monday, officials said.

Both the attacks took place in Mir Ali town, some 40 kilometres (25 miles) east of Miranshah, a stronghold of Taliban and Al-Qaeda-linked militants and the main town in North Waziristan tribal district along the Afghan border.

Two US drones fired two missiles into a militant compound, and minutes later another drone fired two missiles at a vehicle nearby, officials said.

A senior security official in Peshawar said that at least nine militants were killed and another two wounded.

"In the first strike, two missiles destroyed the compound and killed six militants. The second attack killed three more militants travelling in a car," the official told AFP on condition of anonymity.

A security official in Miranshah confirmed the strike, saying earlier that at least seven people had been killed.

"The vehicle was completely burnt and the compound was also destroyed," he told AFP.

It was not clear whether the drones were pursuing any "high-value target" but two intelligence officials in Miranshah said they had received reports from informers on the ground that those killed in the compound were all foreigners.

"We don't know their exact identities but we were informed that there were foreigners inside that compound," one intelligence official told AFP.

Monday's attacks were the fifth and sixth to be reported in Pakistan's tribal areas near the Afghan border since US commandos killed Osama bin Laden in a secret raid in the Pakistani city of Abbottabad on May 2.

The new attacks coincided with a visit by US Senator John Kerry to Islamabad -- the first visit by a senior US figure since the raid -- in a bid to smooth relations severely strained by the commando operation.

Secretary of State Hillary Clinton is also poised to visit her country's nuclear-armed ally after Pakistani leaders were left angry and embarrassed by the unilateral raid.

The Pakistani parliament has called for an end to United States drone strikes on its soil and said there must be no repeat of the operation that killed bin Laden.

Washington does not confirm drone attacks, but its military and the CIA operating in Afghanistan are the only forces that deploy them in the region, aiming to eliminate Taliban and Al-Qaeda militants.

The US strikes doubled last year, with more than 100 drone strikes killing over 670 people, according to an AFP tally, and the CIA has said the covert programme has severely disrupted Al-Qaeda's leadership.

The strikes inflame anti-American feeling in Pakistan, which worsened after a CIA contractor shot dead two Pakistani men in a busy Lahore street in January, and again after the bin Laden raid.

The raid also rocked Pakistan's seemingly powerful security establishment, with its intelligence services and military widely accused of incompetence or complicity over the presence of bin Laden close to a military academy.

US President Barack Obama has said that his country reserves the right to act again on Pakistani soil.

But on Monday, after Senator Kerry's visit, Pakistan said it would work with the United States on future operations targeting militant leaders in the country.

"It was ... agreed that the two countries will work together in any future actions against high-value targets in Pakistan," said Pakistan's foreign ministry.