A mud volcano has caused an explosion in the Caspian Sea offshore Azerbaijan, close to state-controlled Socar's extensive oil and gas fields’ infrastructure.

The cause of the blast, which saw a column of fire shoot into the sky on Sunday, was not immediately determined, but Socar said preliminary information indicated it was a mud volcano.

None of the operator’s platforms were damaged in the blast, production at the facilities has not been impacted and there have been no reported injuries.

A Socar spokesperson was quoted by the Azerbaijani news agency APA as saying the explosion occurred about 10 kilometres from its Umid gas field, which lies about 72 kilometres offshore.

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Mark Tingay, a mud volcano expert and adjunct associate professor at Australia’s University of Adelaide, was quoted by The Guardian newspaper in the UK as saying the explosion “certainly could be a mud volcano”.

Tingay added that the location “fits roughly” with a mud volcano called Makarov Bank, which exploded in 1958, releasing a column of flame 500 metres to 600 metres high and 150 metres wide.

Socar on Monday said the flames were dying down although methane and other gases have been observed at the explosion location.

The Caspian Sea blast followed last Friday’s blaze on the ocean surface west of Mexico's Yucatan peninsula, which Mexican state oil company Pemex blamed on a gas leak from a subsea pipeline.