Where is the Ruang volcano and why has a tsunami warning been activated after its eruption?

Authorities in Indonesia have evacuated thousands of inhabitants from the vicinity of the Ruang volcano, after a series of eruptions in recent days sparked fears of a tsunami.

Where is the Ruang volcano?

The volcano is located on Ruang Island, which is part of the Sangihe Islands in northern Indonesia. Some 2,400 feet in height, it is a stratovolcano - a conical-shaped, steep-sided form of volcano that is characterised by explosive eruptions.

The volcano first began spewing plumes of lava, rock and ash on Tuesday, and has erupted several times since.

Why has a tsunami alert been issued?

According to Indonesia’s Center for Volcanology and Geological Hazard Mitigation (PVMBG), there are fears that the Ruang volcano could partially collapse into the sea, causing a tsunami.

This is what happened when the volcano erupted in March 1871, leading to the deaths of around 400 people.

The PVMBG has raised the alert level to four, the highest in its four-tied system. The agency warned people on Wednesday not to enter a 6km (3.7mi) area around the crater.

Watch - Ruang volcano erupts in Indonesia:

Nearby residents evacuated amid eruptions

Indonesia’s National Disaster Management Agency said on Thursday that residents of Ruang Island, whose population is just over 800, have been temporarily evacuated.

In a statement, the agency also told people on the neighbouring Tagulandang Island to relocate if they live within a 6km radius of the crater.

“People on Tagulandang Island, especially those who live near the coast, should be aware of the potential for incandescent rocks to erupt, hot clouds and tsunami waves that could be triggered by the collapse of a volcanic body into the sea,” the body said.

Around 11,000 of the 20,000 residents of Tagulandang Island are to be relocated, AFP reported on Thursday.

The airport at Manado, on Sulawesi Island, has been closed.