The death toll from bomb explosions in Pakistan's Mohmand tribal agency has reached 65 after several seriously injured people died in hospital, Press TV reported.
Medics said nearly two dozen people died at a hospital in the town of Yakaghund, while over 100 injured victims are still receiving treatment.
There is confusion among the officials about the nature of the Friday attack.
Some authorities say a small bomb went off outside the main gate of the office of the civil administrator in the town.
Others say a large blast followed after a man on a motorbike detonated explosives outside of the office building.
The blast destroyed scores of shops, several houses and parts of a local jail, allowing at least 35 prisoners to escape.
Rescue operations are underway to save those trapped under the rubble.
Authorities have imposed a curfew in the area and launched an investigation into the attack.
The Pakistani military has recently launched a series of operations in an effort to clear the troubled tribal zone of militants.
Militants have killed hundreds of people in Pakistan this year alone.