Hyderabad: At least sixteen people were charred to death when a massive fire broke out at Vishakhapatnam steel plant after an explosion here on Wednesday, reports said.

According to reports, the blast was caused at the high-pressure oxygen control unit near the Steel Melting Shop at the plant of Rashtriya Ispat Nigam Limited (RINL).

A technical problem at the unit was suspected to be the cause for the mishap. Sources said the explosion could have been caused due to abnormal build up of pressure in the unit.

Vizag Police Commissioner Purnachandra Rao said six bodies were recovered from the site of the explosion.

The fire is known to have injured several people and it is feared that the casualty may shoot up. The victims include officials and permanent and contract workers.

The injured have been admitted to the Steel Plant's General Hospital. This is said to be the worst disaster in the 40-year history of the steel plant.

Also known as the Rashtriya Ispat Nigam Limited (RINL), the steel producing company was set up in 1971. This is the third fire accident in less than two months and the fourth this year.

Two workers engaged by a private company were burnt alive in a blast in the recently commissioned blast furnace-III May 1.

In another fire mishap May 22, a conveyor belt carrying raw material to a new blast furnace completely melted, stalling the production and causing property loss of about Rs.1 crore. There were no casualties.

The blast furnace-III was erected as part of a plan to expand plant capacity to 6.3 million tonnes.

Steel Plant Employees' Union general secretary D. Adinarayana blamed negligence on the part of the management for frequent accidents in the plant.