NEW DELHI, Sept. 3 (Xinhua) -- At least five persons died when a major fire broke out at a gas processing unit of the Oil and Natural Gas Corporation (ONGC) plant in India's south-western state of Maharashtra on Tuesday morning, media reports said.

The corporation confirmed the fire, but didn't comment on the loss of human lives.

The ONGC tweeted: "A fire broke out in storm water drainage early morning today in uran oil and gas processing plant. ONGC fire services and crisis management team immediately pressed into action. Fire is being contained. No impact on oil processing. Gas diverted to Hazira Plant. Situation is being assessed".

The fire broke out at around 7:00 a.m. local time at the ONGC plant located in Navi Mumbai area, near the financial capital Mumbai.

Those who died were the workers at the ONGC, the media reports said.

Toxic smoke is said to have spread inside the plant. The death toll is feared to rise even as fire fighting work is still going on at the plant. It has been more than two hours since the fire broke out at the plant.

The cause of the fire is not known yet. TV channels showed deadly flames coming out of the ONGC plant on fire. Further details of the mishap are awaited.