The cause of the inferno was unclear, but shocking footage showed flames shooting into the sky from the giant blaze.
One person was reportedly injured and three were killed in the blast and eyewitnesses said workers were at the site when it went up in flames.
According to local residents, the blast was on a major pipeline operated by Gazprom between the villages of Kalinino and Yambakhtino.
The Urengoy-Pomary-Uzhgorod pipeline was built in the early 1980s and transports gas from Russia via Ukraine to Europe.