A blast occurred near the National Database and Registration Authority (Nadra) office on Nisatta Road in Mardan, Khyber Pakhtunkhwa, Pakistan on Tuesday, killing at least 12 people and leaving 25 injured.

Rescue 1122 sources said at least 12 people were killed in the blast which took place at a time the office was crowded with people.

Deputy Inspector General Mardan Division Saeed Wazir told DawnNews it was a "suicide attack carried out by a bomber".

The DIG added that a security guard posted at the office stopped the bomber at the gate, after which he detonated his suicide vest. The suicide attacker was on a motorbike and rammed it into the gate after being denied entry, he said.

Conflicting reports suggest that explosives may have been planted on a motorcycle parked near the Nadra office.

According to initial reports, the blast took place near the gate of the office and damaged doors and windows in the building. Several people are said to be injured, with some in serious condition.

Human body remains are strewn across the blast site. The death toll is feared to rise.

The area has been cordoned off as rescue and security sources rushed to the site. The injured are being shifted to Mardan Medical Complex. An emergency has been declared at all medical facilities in the area.

The office is located on the link road that connects Charsadda to Multan.