Orakzai had become a sanctuary for insurgents routed by the army’s campaign in South Waziristan, notably Tehrik-i-Taliban, an umbrella organization of militant groups operating in the tribal regions. Orakzai was also a stronghold of the Taliban leader Hakimullah Mehsud, who is generally believed to have been killed in a airstrike in January.

Army officials said over the weekend that militants fleeing other tribal regions also had taken refuge in the remote, thickly forested Tirah Valley in Khyber.

Pakistani officials say that more than 250 militants have been killed in recent offensives in the Orakzai and Khyber tribal regions, although the figures cannot be verified. Journalists are barred from the areas.

While the Pakistani military is thought to have gained the upper hand in the tribal regions, militants have continued to target civil and military installations. Security forces foiled an attempt by militants two weeks ago to retake control of a post in the Bezoti area of Orakzai.

Also Monday, at least six people were killed in clashes in the Abottabad district over the renaming of North-West Frontier Province. The police fired tear gas to quell the unrest, which paralyzed the district in recent days. Protesters claimed that the police opened fire on them, but officials said that the police had fired only rubber bullets. Last week, a suicide bomber killed 42 people at a ceremony being held to celebrate the renaming.