At least 26 people were killed and 52 injured in a suicide blast which hit a government building in Pakistan's northwestern province of Khyber Pakhtunkhwa on Tuesday, Xinhua reported.

Provincial Information Minister, Mushtaq Ghani, told media that at least 26 people lost their lives and 52 are injured in this suicide attack, while six were in critical condition.

According to Deputy Inspector General of Police, Sayyad Khan, the incident took place when a suicide bomber detonated his jacket at the main gate of the National Database and Registration Authority (Nadra) at Dosehra Chowk area of Mardan, a district in the Khyber Pakhtunkhwa province.

Khan said the attacker was around 20-25-year-old and wanted to light up the bomb inside the building, but he exploded himself at the security gate when the guard searched him.

The bomb disposal squad estimated eight kilograms of explosives, along with ball bearings, was used in the attack.

A splinter group of Pakistani Taliban named "Jamaat-ul-Ahrar" claimed responsibility for the attack.