Pakistani officials say a roadside bomb blast near a minority Shi'ite religious procession has killed at least seven people, including three children.
Authorities say 30 people were wounded in the attack Saturday in the northwestern city of Dera Ismail Khan.
The Pakistani Taliban often carries out such attacks.
The attack came as Shi'ites are observing the Muslim holy month of Muharram. Sunni extremists have targeted Shi'ites in the past during Muharram, especially on the holy day of Ashura.
On Sunday, Shi'ites in Pakistan will celebrate Ashura, which commemorates the seventh-century death of Iman Hussein, grandson of the Prophet Muhammad.
Authorities have tightened security across Pakistan to guard against possible attacks on Shi'ite gatherings during Muharram. Pakistan has temporarily suspended mobile phone service in major cities to prevent bombings, which are often triggered by cell phones.