Several other workers of the factory were also injured and two of them are in serious condition, a senior police official said.
Fire tenders were pressed into service and the blaze was controlled by around 3 pm, Assistant Police Commissioner, Jalandhar, Avnit Kaundal said.
"12 factory workers have died in the fire," he said, adding that two of the injured are in serious condition.
"The reason behind the fire is not known and we are probing it," the officer said. Injured have been admitted to city hospitals, he said.
