Three people, includinga 65-year-old woman, died and four others were injured in a blast at a firecracker manufacturing unit near Sattur in Virudhunagar district on Wednesday, police said.
There were 30 people working in some sheds in the unit and the blast occurred in one of them when chemicals were being mixed and packed.
Police said three sheds were razed to the ground in the blast.
The injured have been admitted to hospital.
