Officials in northwestern Pakistan say a bomb blast near a Shi'ite religious procession has killed at least five people and wounded some 90 others.

The explosion Sunday in Dera Ismail Khan came a day after a similar blast targeting Shi'ite Muslims in the same town killed seven people, including three children.

The Pakistani Taliban have claimed responsibility for both attacks.

Pakistan's minority Shi'ites are observing the mourning rituals of Ashura in the holy month of Muharram, the first month of the Islamic calendar.

Sunni extremists have frequently targeted Shi'ites during Muharram.

Authorities have tightened security across Pakistan to guard against possible attacks on Shi'ite gatherings. Pakistan has temporarily suspended mobile phone service in major cities to prevent bombings, which are often triggered by cell phones.