Five persons were killed and around 10 others injured in a blast in a firecracker unit in Tamil Nadu's Villupuram district on Sunday, said officials.

The persons were working in the firecracker unit in a village in Villupuram, around 170 km from Chennai, when the blast occurred.

The blast was so intense that the building came down, trapping and killing the five workers, said a Fire and Rescue Services official.

The injured have been sent to a nearby hospital.