Mount Marapi volcano spews volcanic ash as seen from Nagari Batu Palano in Agam, West Sumatra province, Indonesia, December 4, 2023. (Photo: Reuters)

There were 49 climbers evacuated from the area earlier Monday and many were being treated for burns, he said.

Marapi is one of the most-active volcanoes on Sumatra island and its most deadly eruption was in April 1979, when 60 people died.

This year, it erupted between January and February and was spewing ash around 75 metres-1,000 metres from the peak.

Indonesia sits on the Pacific's so-called "Ring of Fire" and has 127 active volcanoes, according to the volcanology agency.