One of Indonesia's most active volcanoes erupted Monday, spewing flames and clouds of smoke up to a kilometre into the air.

Indonesia's volcanology centre said the nearest villages are about eight kilometres from the mouth of the crater on Mount Soputan, putting residents well beyond the danger zone.

However, people have been advised to stay well clear of the volcano because it may begin spewing lava.

Mount Soputan is on Sulawesi Island, about 2,160 kilometres northeast of the capital, Jakarta.

Indonesia straddles a major fault line known as the "Pacific Ring of Fire" and has more active volcanoes than any other country.

With files from the Associated Press