State vulcanologist Saut Simatupang said on Thursday that no evacuations have been ordered even though many people live along Mount Karangetang's volatile slopes.

He says the volcano has been spilling lava and shooting ash as high as 1,400 meters, prompting authorities to raise its alert to the second-highest level.

The volcano is located 2,300 kilometers north-east of Jakarta on Siau island.

Indonesia is prone to seismic upheaval due to its location on the so-called Pacific 'Ring of Fire,' an arc of volcanoes and fault lines encircling the Pacific Basin.