Three suspected U.S. drone missile strikes killed 24 militants on Friday in Pakistan's northwestern Khyber region on the Afghan border, intelligence officials said, the fourth attack in two days.
The United States has widened drone attacks in Pakistan this year, but almost all of them have been in the North Waziristan tribal region, a known sanctuary for al Qaeda and Taliban militants. Attacks in Khyber are not very frequent.
Khyber agency is home to Lashkar-e-Islami, a militant organisation sometimes allied with the Pakistani Taliban, but which has often clashed with other groups.
The attacks on Friday in Tirah valley occurred within hours of each other. "We have initial reports of some 24 suspected militants killed in three attacks today," one intelligence official in the region said.
Another intelligence official confirmed the figure, saying four suspected militants were killed in the third attack. It could not be immediately verified from independent sources if all the dead were militants, who often dismiss official death toll in such attacks.
A similar strike the day before killed seven suspected militants in the same region.
Pilotless U.S. drones have been attacking al Qaeda and Taliban militants for the past few years in Pakistan's lawless tribal areas on the Afghan border, but there have been a surge in these strikes this year.
Analysts expect the drone strikes to continue and even increase after the Obama administration on Thursday unveiled its year-old strategy in Afghanistan, where U.S.-led NATO troops are fighting a raging Taliban insurgency.
A five-page unclassified summary of the White House review noted substantial but "uneven" progress in its ties with Islamabad over the last year, emphasising greater cooperation with Pakistan to eliminate safe havens in its border areas.
The United States says Pakistan must crack down harder on militants along the border who cross into Afghanistan and attack U.S.-led troops fighting the Taliban.
As it fights Islamist militants, Pakistan has also been bracing for sectarian violence during Moharram, the holiest month for Shi'ite Muslims, which is under way.
Government officials alleged that militants fired mortar shells and struck two houses in the northwestern town of Hangu, killing nine people, including two children and a woman. The region is often a site of sectarian strife.
Tens of thousands of paramilitary and police forces were deployed across the country on Friday to guard Shi'ite rallies on Ashura, the climax of Moharram and the biggest event in their calendar.
On Ashura, Shi'ite Muslims beat and cut themselves during processions to mark the anniversary of death of Imam Hussein, a grandson of the Prophet Mohammad. Sunni militant groups have often attacked Shi'ite gatherings during this period.