Security has been heightened in northwestern Pakistan after a suspected suicide bomber killed 23 people during observances on a Muslim holy day.
Interior Minister Aftab Sherpao says tensions remain high, but that both Sunni and Shi'ite clerics are urging calm. He says a curfew has been imposed and checkpoints set up. Thursday's attack in Hangu, about 200 kilometers from the capital, also injured more than 40 people participating in the festival of Ashura. Army re-inforcements were deployed after angry Shi'ite mobs torched cars and stores. Four other people were killed when gunmen opened fire on a minibus on the outskirts of town.
Ashura marks the death in the seventh century of the Prophet Muhammad's grandson, which led to the original schism between Sunni and Shi'ite Muslims. The majority of Pakistan's Muslims are Sunnis.