The highest volcano on Indonesia's most densely populated island of Java has spewed thick columns of ash high into the sky, triggering panic among people living nearby. There were no immediate reports of casualties.
Mount Semeru's sudden eruption in Lumajang district in East Java province left several villages around its slopes blanketed with falling ash.
The eruption was accompanied by a thunderstorm and rain, forming thick mud, destroying at least one bridge connecting two main villages of Pronojiwo and Candipuro, as well as hampering evacuations, Lumajang district head Thoriqul Haq told TVOne.
"Thick columns of ash have turned several villages to darkness," Haq said, adding that several hundred people were moved to temporary shelters or left for other safe areas.
Television reports showed people running in panic under a huge ash cloud, their faces wet from rain mixed with volcanic dust. The 3,676-metre Semeru had last erupted in January, with no casualties.
Indonesia, an archipelago of more than 270 million people, is prone to earthquakes and volcanic activity because it sits along the Pacific "Ring of Fire," a horseshoe-shaped series of fault lines.
Australian Associated Press