The fire at the factory in Karachi was one of worst infernos the country has seen.
The blaze broke out just a few hours after another fire at a factory in Lahore that left 25 people dead.
"The bodies were iron hot. We got burnt even if we tried to carry them to the ambulances with the help of some cloth. The skin of the victims started peeling off and in some cases, their body parts turned into ash," Geo TV quoted Memon as saying.
He said that some of them were overcome by emotion when they saw a mother looking for her sons at the Abbasi Shaheed Hospital.
"All three were burnt alive," he said.