More than 2,100 people living near an erupting volcano on Indonesia’s Sulawesi island were evacuated on Friday due to the dangers of ash, falling rocks, hot volcanic clouds and the possibility of a tsunami.

Indonesia’s volcanology centre recorded at least three eruptions since Friday afternoon, with the maximum height of the eruption column reaching 1,200 metres (3,900 ft).

An international airport in Manado city, less than 100km (60 miles) from the erupting Mount Ruang, remained temporarily closed as volcanic ash was spewed into the air.

Satellite imagery from the Meteorology, Climatology and Geophysics Agency showed the ash had spread to the west, north-west, north-east and south-east, covering Manado and North Minahasa, according to a statement from Indonesia’s transportation ministry.

“We are still monitoring developments in the eruption of Mount Ruang and coordinating with relevant stakeholders … to anticipate the necessary actions to ensure flight safety, security and comfort,” said Ambar Suryoko, head of the regional airport authority.

More than 11,000 people were told to leave their homes located in the affected area. A joint team from the local authorities combed the villages surrounding the volcano and evacuated residents to safer areas by boat.

Officials worry that part of the volcano could collapse into the sea and cause a tsunami, as happened in 1871.

Houses, roads and other buildings were covered by grey volcanic ash, and many roofs were broken by debris spewed from the eruption.

Mount Ruang saw at least five large eruptions on Wednesday, causing the volcanology centre to issue its highest level of alert. People were ordered to stay at least six kilometres (3.7 miles) from the 725-metre mountain (2,378 ft).

The observation from the agency on Friday said white smoke was rising from the main crater with medium to thick intensity.

East of the volcano, Tagulandang island could be at risk if a collapse occurred. Its residents were among those being told to evacuate. Indonesia’s disaster agency said residents would be relocated to Manado, a journey of six hours by boat.

Indonesia, has 120 active volcanoes. It is prone to volcanic activity because it sits along the “Ring of Fire”, a horseshoe-shaped series of seismic fault lines around the Pacific Ocean.