The explosion occurred at the Eidgah market in Parachinar, the capital of Kurram tribal district.
Political administration confirmed that the death toll has risen to 23. Locals believed that the blast was suicide attack, however police and law enforcement personnel have not released any official in this regard.
Pakistan Army contingent has also reached the spot to control the situation.
Large number of people were present at the site when the blast went off. Hospital sources condition of 24 people was very critical.
AFP adds: Amjad Ali Khan, the political administrator of the Kurram district, confirmed the incident and the toll.
A doctor at the district headquarters hospital, where the wounded were taken, told AFP most of the injured were in “critical condition” and said the death toll could increase.
No one immediately claimed responsibility for the attack, but the region is known for sectarian clashes.
Pakistan has been battling an insurgency since 2004 that has claimed the lives of tens of thousands of civilians and security forces personnel.
Overall levels of violence have decreased this year following a nationwide military-led offensive against extremists across the country, blocking their sources of movement, communication and funding.