At least six people were burnt to death when a reactor exploded in manufacturing unit of a pharmaceutical firm in the southern Indian state of Andhra Pradesh on Monday, said police.

The explosion took place at Asita pharma and drugs factory in Mankhal industrial area of Maheswaram on the outskirts of Hyderabad, the state capital, causing a huge fire.

All the victims were workers at the factory working in the early hours, said police.

Industrial incidents are common in India.