A suicide bomber detonated his explosive device outside a government tax office in the northwest Pakistani city of Mardan on Tuesday, killing at least one person and wounding nine others, police said.
The attacker also fired gunshots as he approached the tax revenue office, the city police chief, Faisal Shahzad, told The Associated Press.
He said at least two of the wounded were in critical condition.
Hours after the attack, Ahsanullah Ahsan, a spokesman for the Jamat-ul-Ahrar militant group, claimed responsibility and warned that they will continue such attacks in the future. Pakistani militants have long attacked government offices and security forces in a bid to install their own harsh brand of Islamic law.
The Pakistani military has launched multiple offensives against militant hideouts, but the insurgents have proven resilient.
An Easter Sunday suicide bombing targeting Christians killed over 70 people in the eastern city of Lahore last month.
Mardan is about 50 kilometers (30 miles) northwest of Peshawar, the capital of Khyber Pakhtunkhwa province bordering Afghanistan.