"There were huge flames as high as 70 feet and the whole area of nearly 2-3 kilometres was engulfed in fire and flames."
Dozens of people were being treated in nearby hospitals for burns and other injuries caused by the fire.
The depot, located a short distance south of Jaipur, the state capital, provides storage for petrol, kerosene, and diesel fuel for several state-owned oil companies.
People living near to the plant were ordered to evacuate the area as more than 20 fire engines battled the fire which could be seen from several kilometres away.
Members of the army were also drafted in to help fight the blaze.
"We're asking for expert advice to help us control the fire," Ashok Gehlot, chief minister of Rajasthan, said.
Officials have made no comment on the possible cause of the fire.