WATCH: Ruang volcano in Indonesia erupts after nearly 22 years

After several eruptions in the past two days, over 11,000 people in Indonesia have been told to evacuate the inhabited land near Ruang volcano, as fears of a tsunami prompted by its collapse grow on Thursday, Al Jazeera reported.

Mount Ruang, located in the North Sulawesi Province, first erupted at 9:45pm on Tuesday followed by four eruptions the next day, forcing volcanology agency to raise the alert level to four, the highest on the scale.

The agency also widened the exclusion zone around the crater from four kilometres to six.

Over 800 people were initially evacuated from Ruang to Tagulandang Island, located over 100 kilometres north of Manado. 

However, officials on Thursday morning announced that more people would need to be evacuated due to a widening zone and taken to Manado.

“At least 11,615 residents who are in the risk area must evacuate to a safe place,” Abdul Muhari, the head of the disaster agency’s disaster data, communications and information centre was quoted as saying by the Kompas newspaper.

Authorities are also concerned that a portion of the volcano may collapse into the sea triggering a tsunami like it did in a previous eruption in 1871.

Muhammad Wafid, the head of Indonesia’s geological agency, earlier said Ruang’s initial eruption sent an ash column two kilometres into the sky, with the second eruption pushing it to 2.5 kilometres.

The volcanology agency said volcanic activity had increased at Ruang after two earthquakes in recent weeks.

Indonesia, located along the "Ring of Fire" tectonic fault lines, has 120 active volcanoes.

In 2018, Anak Krakatoa volcano's eruption triggered a tsunami along the coasts of Sumatra and Java after parts of the mountain fell into the ocean resulting in hundreds of deaths.