The bomb went off near a Muharram procession Saturday at Bannu Chungi in Dera Ismail Khan district, Geo News reported.
Bomb disposal squad officials said 17-22 pounds of explosives were used to make the bomb, which had been placed in a garbage can near the procession.
No one has claimed responsibility for the attack yet, CNN reported.
Pakistan has taken precautionary measures to increase security for the religious observance, which culminates Saturday.
Interior Minister Rehman Malik temporarily blocked cellphone service in some cities where intelligence indicated the possibility of bombs being detonated by cellphones. Malik also banned motor bikes for two days in some cities.