Four people were killed and an equal number injured in explosions at two fireworks manufacturing units in Tamil Nadu's Virudhunagar and Salem districts today. 

The incident occurred this morning when workers of the private cracker unit in Kakivadanpatti were mixing chemicals required for manufacturing fireworks, they said, adding the explosion took place due to friction.

A 28-year-old man died and two others were injured in an explosion at an illegal firecrackers manufacturing unit near Athur in Salem, they said.

The three were engaged in manufacturing the crackers when the incident occurred, police said, adding that the unit was being run illegally.

The injured have been admitted to a hospital, they said.

In the other explosion in a private fireworks unit at Kakivadanpatti in Virudhunagar, three persons were killed and two others injured, police said.

Fire tenders were rushed to the spot to put out the fire.

On April 6, four people were killed when chemicals being mixed to make fireworks at two units in Sivakasi, hub of the country's firecrackers industry, in Virudhunagar district exploded.