New Delhi - At least 13 workers were charred to death in a fire at a factory making edible oils in India's southern state of Tamil Nadu, a news report said Thursday.

The fire broke out late Wednesday at the plant in the Valayapatti area, about 350 kilometres south-west of the state capital, Chennai, local official U Sahayam told the PTI news agency.

Six workers sustained burns and the condition of four of the injured was serious, he added.

Local officials who conducted a preliminary inquiry into the incident said some of the victims were child workers.

Although child labour is banned in India, hundreds of thousands of child workers are employed at factories and other establishments due to weak enforcement of the law.

Authorities launched an inquiry into the fire and were investigating whether the factory had proper licences to operate. (dpa)