Three workers were charred to death in a blast at an illegal firecracker unit near Sivakasi in Virudhunagar district on Friday, just a few weeks after an explosion in the same area claimed 38 lives and left more than 60 injured.

The illegal unit was located at Vijayakarisalkulam. The victims, engaged in making fancy firecrackers, were K. Kumar (45), J. Bhagyaraj (26) and K. Kaliraj (26) of Vallampatti.

The incident occurred even as officials were taking remedial steps to improve safety in such units.

The police said the blast was triggered around 10 a.m. by a fire that broke out in a small asbestos-roofed room behind the residence where the owner Shanmugaiah, 60, and his son S. Chellapandiyan had been making crackers illegally for several years.

The previous incident took place at Om Sakthi Fireworks Industries, at Mudalipatti, on September 5.

Since September 10, officials of the Petroleum and Explosives Safety Organisation have been inspecting cracker units.