A suicide bomber blew himself up among worshippers streaming toward a Shiite mosque in central Pakistan, killing 24 people and wounding dozens more. The attack in the city of Dera Ghazi Khan on Thursday risks sparking sectarian fury in a country already battling rising militancy along the Afghan border and tension with India over the Mumbai terrorist attacks. The bomb detonated as a crowd approached the mosque for an evening prayer ceremony. Television footage showed bystanders and emergency workers trying frantically to help victims lying in the darkened street. Athar Mubarak, the city police chief, said the bomb contained metal balls and nails. As well as the 24 dead, another 40 people were wounded, he said. “Evidence collected from the spot indicates that a suicide bomber blew himself up in the crowd,” Mubarak said. Hasan Iqbal, the city's top administrator, said he believed that the Shiite gathering was deliberately targeted. He wouldn't say whether Sunni extremists were likely behind it and there was no immediate claim of responsibility. However, relations between this Muslim nation's strong Sunni majority and Shiite minority have already been tested by a series of attacks attributed to sectarian extremists. Much of the violence has been in Pakistan's northwest, where the Taleban and other violent Sunni groups have gained ground. In the deadliest recent incident, a car bomb killed 29 people and wounded scores near a Shiite mosque in the regional capital, Peshawar, in December. On Tuesday, a grenade attack killed at least one person at a Sunni mosque in the town of Dera Ismail Khan. Meanwhile, a suicide attacker detonated an explosive-laden car near a police station in Mingora, the main town in Pakistan's Swat valley, wounding a dozen officers and destroying part of the building, said Dilawar Khan Bangash, the police chief.