A fire engulfed a factory in southern Pakistan on Friday, killing 15 labourers, an official told dpa on Friday.
The fire broke out inside the premises of a chemical factory in a congested Karachi neighbourhood, rescue official Mobeen Ahmed said.
At least 15 bodies have been retrieved from the rubble of a building that partially collapsed, but a rescue operation is still under way, Ahmed said.
More than 20 labourers were inside the compound when a highly flammable chemical caught fire. It spread to the entire building shortly thereafter.
Hazardous working conditions in factories and mines in Pakistan mean that fires occur regularly.
In 2015, at least 30 people were killed when the building of a factory collapsed in the eastern city of Karachi.
More than 250 labourers were killed when a fire broke out at a garment factory in Karachi in 2012.
That incident drew global outrage because the factory was supplying products to global chains including German retailer KiK.