At least 32 people were killed when a blaze erupted at a fireworks warehouse in southern India ahead of a major Hindu festival.

The victims in last night's explosion were mainly traders buying fireworks in bulk as millions of Hindus prepared to celebrate Deepavali, the festival of lights, the Press Trust of India (PTI) reported. Setting off fireworks is a major part of the celebration's festivities.

Police pulled 32 bodies, most of them charred remains, from the warehouse in Pallipat near Chennai, the capital of the southern Indian state of Tamil Nadu, PTI quoted local administrator Palani Kumar as saying.

Three people were being treated in hospital for burns, Kumar said. The cause of the fire was not immediately known. Police have arrested two people, including the warehouse owner, as they investigate.

Several big cities and small towns of India have illegal factories making fireworks, which are used during festivals, weddings and religious ceremonies. Some illegal workshops operate in homes.

Nearly all the clandestine factories have minimal safety standards and fatal explosions are a regular occurrence.