An underground coal mine in Sawahlunto, West Sumatra of Indonesia exploded because the appearance of methane, killing three miners while 30 others were still trapped under the rubble, local news sources said on June 17.

“We suspected that the explosion may have been caused by the oozing out of methane, which is usually found in coal mines,” Marpaung, technical and environmental director of the mineral, coal, and geothermal directorate general at the Ministry of Energy and Mineral Resources was quoted by Antara news agency as saying.

“Three dead miners had already been pulled out of the tunnel, and deep in the tunnel there were still about 30 others whose fate was still unknown," he added.

Search and rescue operation is underway. No further information is available at the stage.

Indonesia has some of the world’s largest coal deposits and is a major coal exporter./.