At least four persons were killed and 45 were missing as a major fire on Tuesday destroyed a big oil-drilling platform of Oil and Natural Gas Corporation off Mumbai coast, disrupting crude production from the country's biggest oil field.

Petroleum Minister Mani Shankar Aiyar told PTI in New Delhi that three persons were confirmed dead when the ONGC [Get Quote] platform, located about 160 kms from the coast, caught fire at around 1630 hours.

Late on Wednesday night, ONGC officials in Mumbai said one more body has been fished out from the Arabian Sea.  

Aiyar earlier said there were 385 people on the platform when the incident took place.

ONGC officials said 331 people were rescued by Coast Guard and Navy ships. 

They said the "casualties are very minimal".

Several ONGC personnel abandoned the platform and jumped into the Arabian sea, Coast Guard sources said.

The fire was apparently caused due to collision of a vessel docked nearby in high tide.

"The platform has been completely destroyed. There is bound to be some loss of life and injuries," Aiyar said.

The army, navy, coast guard and air force pressed into service eight ships, three aircraft and four helicopters for rescue operations and they rescued 331 people by dropping life rafts.

The blaze died as the platform collapsed.

ONGC Chairman and Managing Director Subir Raha said the platform, which gathered oil from up to 20 wells and supplied 80,000 barrels per day, would take several months to return to normal production.

Prime Minister Manmohan Singh [Images], who is scheduled to make an aerial survey of the affected areas of Mumbai and other parts of Maharashtra, is taking Aiyar along with him for a first hand assessment of the damage. Singh condoled the deaths in the oil platform fire.

This is the second major fire in four years at the Mumbai High fields.