At least 105 people were killed in a fire that swept through a garment factory overnight in the Pakistani port city of Karachi, a local official said Wednesday. The toll from the fire, which continued to burn on Wednesday morning, was based on information reported by hospitals treating the victims, said Muhammad Waseem, an official at the health department of Sindh Province, where Karachi is located. A child is among the dead, and at least 25 people have been injured by the fire, said Zakir Khan, of the Karachi Fire Department. All the victims were employees of the factory, he said. Firefighters were trying to bring the blaze under control, Khan said, but their task was made more difficult because they couldn't enter several portions of the building that were in danger of collapsing. Dozens of people may be trapped in the basement of the building, according to Khan. A rescue operation is under way to try to save them. Several workers who were trapped by the fire jumped out of the upper floors. Video broadcast by CNN affiliate Geo TV showed large crowds of anxious people gathered outside the smoldering building.