Indonesia’s most active volcano erupted, sending a river of lava and burning clouds of gas flowing 3,000 meters (9,850 ft) on its slopes.
The noise of the eruption could be heard 30 miles away, officials said. No casualties were reported.
It has been the highest lava flow on Mount Merapi since authorities raised the danger level in November, said Hanik Humaida, head of the Center for Geological and Volcanic Hazard Mitigation in the nearby city of Yogyakarta.
She said the volcano’s lava dome was rising rapidly, causing hot lava and gas clouds to flow down its slopes.
After the morning rain, the ashes turned to muck in several villages. More than 150 people, mostly elderly, living less than 3 miles from the crater were evacuated to barracks set up for displaced people.
In November, authorities evacuated nearly 2,000 people living in the mountains in Magelang and Sleman districts, but most have since returned.
The alert is maintained at the second highest level, and authorities have told people to stay out of a danger zone around the crater.
The 2,968-meter volcano on the densely populated island of Java is the most active of dozens of Indonesian volcanoes and has erupted repeatedly until late. The last major eruption of Merapi, in 2010, killed 347 people.
Indonesia, an archipelago of 270 million people, is prone to earthquakes and volcanic activity, as it sits along the so-called “Ring of Fire” of the Pacific, a series of horseshoe-shaped seismic fault lines.