Last Updated 3/27/09 7:25 PM EST
During Friday prayers, a suicide bomber attacked a two-story mosque in Jamrud, leveling the building and killing at least 76 of the roughly 300 worshippers inside at the time. Nearby hospitals report as many as 170 were receiving treatment after the blast.
Rescue operations are ongoing, and so far no one has claimed credit for the attack, the most serious attack in the restive Khyber Agency in recent memory. Reuters is reporting that many local officials and security forces worship at the mosque, which suggests they may have been the target.
Jamrud lies along the Khyber Pass, the road that links Pakistan and Afghanistan and is the key supply line for NATO forces. The Pakistani military has been engaged in a military offensive against militants in the region, who have made the route intermittently impassable.