A huge explosion shook the Caspian Sea area late Sunday where Azerbaijan has vast offshore oil and gas fields. The blast, that sent plumes of black smoke and flames into the sky, was caused by a mud volcano.

The state oil company Socar said the explosion took place about 10 km from the Umid gas field and 75 km off Azerbaijan’s capital Baku.

“There were no accidents on offshore platforms and industrial facilities under the direct control of Socar, and work continues normally,” the company said in a statement.

Azerbaijan’s Ministry of Emergency Situations also confirmed that no emergencies occurred at offshore oil and gas production nor other industrial and transport infrastructure facilities.

Socar noted that the eruption of mud volcanoes due to their connection with oil and gas fields has led to the release of methane and other flammable gases in the past.

Following investigations by Socar and the Ministry of Emergency Situations, it was said that the remaining small flame in the crater of the volcano does not pose a threat to offshore oil and gas infrastructure and other facilities.

The incident comes hot on the heels of the massive ‘eye of fire’ in the Gulf of Mexico, which took place after the Mexican oil giant Pemex suffered a breach in a subsea gas pipeline near one of its platforms.