Laden may be in Afghan south, says Pakistan

The whereabouts of bin Laden, architect of the Sept. 11 attacks, and top militants such as his deputy, Ayman al-Zawahri, and Taliban leader Mullah Mohammad Omar, are not known but they are suspected of hiding along the rugged Afghan-Pakistani border.

Although both close US allies, tension has risen between Afghanistan and Pakistan over Afghan and US military accusations that militants launch attacks into Afghanistan from the safety of Pakistan.