Police said the remote controlled bomb was planted on Charsadda road within the remits of Dawoodzai police station.
SSC Rural areas Shafaullah said the bus was carrying secretariat employees. He said the bomb was detonated by a remote control device.
10 bodies were taken to Lady Reading Hospital.Eyewitness said several victims were in critical condition with severe burn injuries. Other bodies and 21 injured people were shifted to Charsadda District Hospital.
The hospital administration confirmed that 8 people including two women were killed in the blast.