A fire swept through a slum in Pakistan's largest city, killing 38 people, many of them children, officials and witnesses said Friday. One official speculated the blaze, which broke out late Thursday in the port city of Karachi, could have been triggered by a fire lit by people to stay warm. Authorities were still investigating. Riaz Ahmed, a resident of the slum, said he saw the scorched bodies of two women who died hugging each other. More than 17 makeshift huts were destroyed, he and other witnesses said. Provincial Health Minister Sagheer Ahemd said 38 bodies had been taken to the hospital, among them women and children. Dawn TV News reported up to half of the victims were children.