caspian sea fire
© Twitter / @Liveuamap
While the official cause of the explosion remains to be determined, Azerbaijan's Ecology Ministry said that the blast may have been caused by a volcanic eruption.

A massive explosion was spotted in the Caspian Sea on Sunday, with some reports initially suggesting that it could have been connected with a nearby coastal oil platform.

This, however, was later debunked by the State Oil Company of Azerbaijan Republic (SOCAR), which released a statement saying that there had been no accidents registered on offshore platforms.
"There were no accidents on offshore platforms and industrial facilities under the direct control of SOCAR, and work continues normally. If there is additional information, we will inform the public", the company stated.
​The country's Ministry of Ecology said that the incident is under investigation, and the preliminary cause is said to be a volcanic eruption.

The videos shared online show a large blast in the sea, with flames and smoke rising up from the waters. Some clips were filmed from the coastline, while others appear to have been filmed from an oil vessel.

One reporter shared several photos of the explosion.