More than 500 people were forced to evacuate the slopes of Mount Karangetang as the mountain spewed lava and clouds of hot gas on the island of Siau, just north of Sulawesi.
In 1997, pyroclastic clouds of volcanic debris cascaded down the slopes of Karangetang, killing seven people. An eruption in 1974 forced the entire population of Siau to evacuate to nearby islands.
An explosion within Mount Soputan, one of Indonesia’s most active volcanoes, sent a plume of ash soaring high above northern parts of Sulawesi.
There were no reports of injuries or damage, but villages near the base of Soputan were covered in volcanic debris.
Many residents were wearing face masks, local volcanologist Sandy Manengke told the Associated Press.
Farmers who regularly work soil along the mountain's fertile slopes were told to stay clear of the peak.