Mount Sinabung in Karo erupted at 10:17 a.m. local time on 31 August 2026, sending ash about 3,500 metres above the summit, or 5,960 metres above sea level in ANTARA News. The Geological Agency raised the alert at 12:30 p.m. to Level III, Phys.org's second-highest level. Phys.org writes a 6 kilometre crater exclusion; ANTARA News splits a 3 kilometre summit radius from a 6 kilometre south-southeast sector. Only Phys.org says no casualties were reported immediately.
Mount Sinabung in Karo District erupted at 10:17 a.m. local time on Monday 31 August 2026, ANTARA News reports. Phys.org says Mount Sinabung on the Indonesian island of Sumatra erupted that Monday and sent an ash column about 3,500 metres above the summit. ANTARA News gives the same 3,500 metres above the summit, or roughly 5,960 metres above sea level. Phys.org carries the 3,500 metres above the summit as well.[1], [2]
Indonesia's Geological Agency, part of the Ministry of Energy and Mineral Resources, raised the alert to its second-highest level, Phys.org reports. ANTARA News writes the same step as a move from Level II (Caution) to Level III (Alert), effective 12:30 p.m. local time. Lana Saria, who heads the Geological Agency, describes the event in Phys.org as an initial eruption. A larger one could follow.[1], [2]
Phys.org reports a 6 kilometre exclusion radius around the crater, set on the agency's monitoring of the current unrest. ANTARA News instead prohibits activity within a 3 kilometre radius of the summit and within a 6 kilometre sectoral radius in the south-southeast sector; relocated villages were placed off limits, and people living near rivers from Sinabung were urged to watch for lahar floods. Phys.org says the volcano's activity in recent years has displaced about 30,000 residents, and that no casualties, evacuations or flight disruptions were reported immediately. ANTARA News does not state whether casualties occurred.[1], [2]
