The bomber exploded himself up amidst the people gathered in the Excise and Taxation Office in Mardan district of Khyber Pakthunkhwa, District Police Officer Faisal Shahzad said.
Before detonating explosive vest wrapped around his body, the bomber fired two shots, Shahzad said.
The Police and security forces rushed to the site and cordoned off the area.
The injured have been shifted to nearby hospitals.
