One RIL employee was injured in the fire, a company spokesperson said.

RIL President (Refinery) P K Kapil said the refinery operations would not be affected by the fire as it was confined to only the secondary vaccum distillation unit.

"A fire broke out this morning at a secondary unit. As a safety precaution, adjacent plants were shutdown (to isolate the fire). Fuel source was also cut," the spokesperson said adding 95 per cent of the fire had been doused.

The units shut would be restarted at the earliest, he said. "There is no impact on the refinery throughput."

Refining experts said the fire may affect output from one of the two crude distillation units of the 33 million tonnes a year Jamnagar refinery as repairs may take a couple of weeks.

Jamnagar police said emergency teams rushed to the spot as soon as the fire alert was sounded around 10:30 am and that prima facie the fire appeared to have been caused by a spark.

Police sources said, the fire erupted in the Hydro Treated section of the refinery, prompting the officials to evacuate people and cut off the inflow of crude into all the section.

Eyewitness said leaping flames and billowing smokes were witnessed near the refinery even as a large number of fire tenders in and around Jamnagar were pressed into service.

"One person has received burn injuries and is being treated. The plant where the fire broke out has been isolated and work is underway to douse the flames" Jamnagar district collector V P Patel told PTI.

On the impact of the fire on production, a senior company official said, "It is too early to comment at this juncture. We will come to know about it only after we assess the damage," he added.