The fire was visible from the coast of Azerbaijan. (Via IRNA)

A huge fire has erupted off the Caspian Sea coast of Azerbaijan, where the Central Asian nation operates vast offshore oil and gas fields, amid conflicting reports of blasts and official insistence that no incidents have occurred at the platforms.

State Oil Company of Azerbaijan Republic (SOCAR) emphasized on Sunday that its offshore gas platforms in the Caspian Sea were safe.

No incidents have happened at the offshore fields and industrial structures controlled by SOCAR, work continues normally, SOCAR spokesman Ibrahim Ahmadov declared.

However, videos and photos published on social media showed smoke rising above the sea off the coast of Azerbaijan, causing some to speculate that there had been an explosion on an offshore platform.

Azerbaijan�s Oil Workers� Rights Protection Committee also confirmed that a fire had broken out at the Umid gas field at an old exploration site. Umid is located 75 kilometers off the coast of the capital, Baku.

SOCAR said the most likely reason for the smoke was a mud volcano, according to Russia�s RIA news agency.

This is while the Azerbaijani APA news agency further cited Ahmadov as saying that a blast took place about 10 kilometers from the Umid gas field

Ahmadov was also quoted by the Interfax news agency as insisting that offshore platforms and industrial facilities under direct control of SOCAR work normally, no accident happened there.

Azerbaijan�s Republican Seismological Survey Center (RSSC) also attributed the blast and the fire to a mud volcano, which spews both mud and flammable gas.

When an eruption occurs on land, a certain amount of fire is thrown into the air, after which the volcano begins to erupt with mud lava, said RSSC Director Gurban Yetirmishli, as quoted in an Interfax report.

A similar process takes place at sea, just behind the thickness of the water we cannot see the mud that the volcano erupts, Yetirmishli further explained.

He also noted that the Caspian Sea has a high concentration of mud volcanoes, which discharge fire and mud for about 10-20 seconds.

Offshore fields are the main source of Azerbaijan�s gas output, the bulk of which is exported to Europe.