Thousands of people were forced to flee after the Mount Karangetang volcano, on the Siau Island in the North Sulawesi province, started spitting clouds filled with lava and gas. The eruption was recorded by Yulia Tatipang, head of the Karangetang volcano observation post. He said there was no reports of injuries or any serious damage.
Villagers were said to be alarmed to see hot ash spewing down the slopes late on Monday night.
The falling ash and sulphur also blanketed many villages surrounding the slopes.
Mr Tatipang waned people to stay at least 3km away from the crater, as the alert level of the volcano is still at the second-highest level.
Karangetang’s last massive eruption was in 2011, which killed four people.
Is Bali safe?
The Foreign and Commonwealth Office (FCO) is still advising people not to travel within four kilometres of the Mount Agung crater in east Bali, which has been erupting continuously since 2017.
The huge volcano blew two years ago, following a huge eruption which sent ash spewing into the sky.
This eruption caused hundreds of flights to be cancelled, leaving more than 120,000 people stranded.
On December 30, plumes of white smoke and ash then filled the sky once more, as the mountain erupted again.
The FCO is also warning tourists and residents to stay at least seven kilometres away from the Mount Sinabung crater in Kalo Regency, North Sumatra.
This major eruption shot ash and rock more than 5,000m (16,400ft) into the sky in February last year.
The country’s volcanology agency said at the time: “This was the biggest eruption for Sinabung this year.”
Why does Indonesia get so many volcano eruptions?
Indonesia lies on the Pacific Ring of Fire, which is a horse-shoe shaped ring of volcanoes and fault lines.
Some of the world’s most active volcanoes lie along the ring, in countries such as Chile and Japan.
At least 129 volcanoes are active in Indonesia, including the Karangetang volcano.