Indonesian authorities closed an airport and residents left homes near an erupting volcano Thursday due to the dangers of spreading ash, falling rocks, hot volcanic clouds and the possibility of a tsunami.

Mount Ruang on the northern side of Sulawesi Island had at least five large eruptions Wednesday, causing the Center for Volcanology and Geological Disaster Mitigation to issue its highest-level alert, indicating an active eruption. The crater emitted white-gray smoke continuously during the day Thursday, reaching more than 500 metres above the peak.