Mud volcano erupts in Azerbaijan Published duration 24 September 2018

image copyright Ministry of Ecology of Azerbaijan image caption Eruptions are expected to continue for some time

A mud volcano has erupted in Azerbaijan, sending plumes of black smoke and flames up to 300m (980ft) into the sky.

Government officials say cracks up to 40m deep have appeared in the area after the Otman-Bozdag volcano became active on Sunday.

The mud volcano, said to be the world's second largest, is located near the capital Baku.

It was not immediately clear if it posed any danger to local residents.

Social media users have been sharing videos of the unusual event.

About 400 of the world's estimated 1,000 mud volcanoes - also known as sedimentary volcanoes - are in Azerbaijan.

They are smaller than normal volcanoes, and are often located on oil fields.