At least six people were killed and 38 others injured when a suicide bomber collided his motorcycle with a bus on University Road in Peshawar.
According to police sources, the target of blast was commissioner Peshawar Sahibzada Anees, who passed moments before the blast.
The dead and injured were shifted to the Khyber Teaching Hospital, where some injured are said to be in critical condition and death toll is feared to climb.
Police and law enforcement agencies cordoned-off the investigations and launched the probe.
Bomb disposal officials said the explosives weighed up to six kilograms. Banned outfit Tehreek-e-Taliban Pakistan (TTP) has claimed the responsibility of attack.
