Mount Merapi, Indonesia's most active volcano, erupted Wednesday emitting a river of lava into the mountain below and gas clouds into the sky.
The eruption set off the volcano's longest lava flow since the danger level for Merapi was raised in November, Hanik Humaida, the head of Yogyakarta's Volcanology and Geological Hazard Mitigation Center, told The Associated Press. Sounds of the eruption could reportedly be heard almost 18 miles away.