Tribal backlash over al Qaida offensive

A roadside bomb killed three police officers and a civilian in the latest of a series of attacks raising fears that a bloody offensive by Pakistani forces against al-Qaida militants could be provoking a broad backlash.

The bomb exploded late last night in northwestern Pakistan as an army vehicle passed as part of the military’s sweep against suspected terrorists holed up in the rugged tribal regions along the Afghan border, police said.