Mount Merapi erupted several times on Monday afternoon, spewing lava down its southern and southeastern slopes.
Three major eruptions were recorded at 2:04 p.m., 2:24 p.m. and 3:15 p.m, according to reports from Merapi monitors and as reported by kompas.com. Other eruptions may have occurred, but thick clouds obstructed observations of the mountain.
Merapi has seen an increase in volcanic activity over the past week, leading officials to raise warnings to the highest level.
Merapi last erupted in 2006, when sending an avalanche of blistering gases and rock fragments racing down its slopes, killing two people.
A similar eruption in 1994 killed 60, while 1,300 people died in an eruption in 1930.