Pakistani officials say their forces have destroyed a key militant compound in an effort to clear insurgents from the northwestern Khyber tribal district.

Officials say security forces blew up the headquarters of the hardline Lashkar-e-Islam group Tuesday.  No casualties were reported.

Pakistani forces have been working in Khyber's Bara area for the past four days to tackle militants who were threatening the northwestern city of Peshawar and a supply route for U.S. and NATO forces in neighboring Afghanistan.

Khyber is one of several semi-autonomous tribal areas bordering Afghanistan where Pakistan's federal government has limited authority.  The area is at least 100 kilometers northeast of the region across the Afghan border, in Khost province where a coordinated counterattack by NATO and Pakistani troops on Monday repelled militant fighters.

Officials in Islamabad say U.S. Assistant Secretary of State Richard Boucher expressed concern about the situation in Pakistan's tribal areas during a visit this week to the capital.