MANADO, Indonesia (AP) — 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 meters (1,600 feet) above the peak.

People have been ordered to stay at least 6 kilometers (3.7 miles) from the 725-meter (2,378 foot) mountain. More than 11,000 people live in the affected area and were told to leave. At least 800 have done so.

An international airport in Manado city was temporarily closed Thursday as volcanic ash was spewed into the air.