Residents of Karachi, Pakistan's largest city, have begun holding the funerals for the 45 people killed in a car bomb explosion outside a mosque that also wounded about 150 others.
Thousands of people turned out for the funerals Monday.
Schools and businesses are closed as the city observes a day of mourning for the people killed in the blast Sunday as worshipers were leaving evening prayers in a neighborhood dominated by minority Shi'ite Muslims. Several buildings caught fire and people were trapped under the rubble of structures that collapsed. Women and children are among those wounded.
Paramilitary officer Pervez Ahmad says a chemical used in the blast caught fire and spread the destruction.
No one has claimed responsibility, but Sunni Muslim militants with links to al-Qaida and the Taliban frequently target their Shi'ite neighbors across Pakistan, especially in Karachi.
According to the independent Human Rights Commission of Pakistan, at least 2,284 people died in ethnic, sectarian and political violence last year in Karachi.
Shi'ite Muslims attend funeral prayers who those killed in a bomb attack a day earlier in Karachi, Pakistan, March 4, 2013.
Shi'ite Muslims shout slogans during a protest against the bomb attack in Karachi, in Quetta, Pakistan March 4, 2013.
A man stands in an apartment that was damaged in a car bombing that killed scores of people, in Karachi, Pakistan, March 4, 2013.
Medics and civilians gather at the site of a bomb blast in Karachi, Pakistan, March 3, 2013.
Men carry the body of a man from the site of a bomb blast in Karachi, Pakistan, March 3, 2013.