A volcano on Indonesia’s most densely populated island erupted Sunday, forcing more than 2,000 people to evacuate as ash blanketed a number of nearby villages and blocked out the sun, while glowing streams of lava descended from the slope and flowed toward an important local river. It was the second eruption for Semeru, the tallest mountain on the island of Java, in two years—after another devastating volcanic event last year killed more than 50 people. No immediate reports of casualties were recorded Sunday, however, though many local roads have been closed and officials warned two regional airports to be vigilant should flying conditions worsen due to the falling debris. The eruption also follows recent seismic activity in the region—including a series of earthquakes that killed more than 300 people on Java last month.