The blast took place at the factory near Pirda village in Bemetara district, about 23 km north of Raipur, the capital city of Chhattisgarh.
Following the blast, authorities rushed fire brigade teams, police contingents and State Disaster Response Force (SDRF) personnel to the spot to carry out the rescue work.
Officials said the number of casualties is likely to increase as many people are feared trapped under the huge mounds of debris. Local media reports said at least 100 people were working in the factory when the blast took place.
MNA/PR