New Delhi  - The death toll from a huge fire at an oil depot near India's northern city of Jaipur rose to 12 Monday as the blaze raged for the fourth day, triggering health concerns for residents.

The fire at the state-run Indian Oil Corp (IOC) depot on the outskirts of Jaipur started Thursday evening and engulfed at least 11 tanks containing 8 million litres of oil.

At least two of the tanks were still ablaze while thick black smoke billowed out of the remaining containers.

As a veil of soot descended over the city's suburbs, about 100 people living near the depot reported to hospitals complaining of respiratory and eye problems as well as skin allergies, senior administration official Kuldeep Ranka told reporters.

One body was retrieved from the debris of a nearby factory, and an IOC staffer succumbed to burn injuries in hospital, taking the death toll to 12, the PTI news agency reported quoting police.

More than 30 of the 150 people injured in the fire were receiving treatment at a government hospital in Jaipur.

Solid particles of carbon mixed with sulphur and other hydrocarbons were descending to the ground, officials said.

"Pollution experts say the suspended particulate matter is higher than the permissible limit but there no immediate health hazards that could pose a threat to citizens. There are no toxic gases," Ranka said.

Teams of doctors and paramedics fanned out in the region to attend to those with medical complaints, he added.

Although the flames had subsided, the situation was still dangerous because of flammable material at the depot. Two blasts occurred Sunday night as barrels of lubricants in the compound exploded due to intense heat.

The IOC said it had no option but to allow the petroleum stock to burn off before firefighters could safely approach the site.

Chief Fire Officer Ishwarlal Jat said fires in the two remaining petrol tanks would probably take one more day to completely burn out.

Officials estimated the losses at up to 10 billion rupees (about 200 million dollars).

Besides burning fuel worth 5 billion rupees, the fire caused damage to hundreds of shops and factories in the industrial area, estimated at another 5 billion rupees.

Rail and road traffic was being diverted to alternate routes.

India's federal Petroleum Ministry ordered an inquiry into the cause of the fire, while preliminary investigations showed a leak in a pipeline. (dpa)