The explosion took place at the National Database Registration Authority (NADRA) office in Mardan district of the province, Dawn online reported.
The bomber detonated his suicide vest after being stopped by the security guard deployed at the office gate.
The death toll is feared to rise.The area has been cordoned off as rescue and security sources rushed to the blast site.
The District Police Officer Mardan said it is too early to determine the nature of the blast at this time. Any group is yet to claimed responsibility for the bombing.