The volcano on the remote island of Halmahera erupted at 9.12am on Monday (local time) for about five minutes, projecting ash into the sky as high as 5km, officials said.
A smaller eruption was recorded on Friday.
The alert status of the volcano remains at the second-highest level, Hendra Gunawan, head of Indonesia's Volcanology and Geological Hazard Mitigation Centre, said in a statement.
All activities within a 5km radius of the volcano were prohibited, he added.
"If it starts to rain ash, we recommend people who are near the volcano to wear a mask and glasses," Hendra said.
Footage of the eruption shared by the centre showed clouds of grey ash billowing from the crater. The official said a booming noise was also heard.
No evacuation of residents has been reported so far.
Indonesia sits on the Pacific "Ring of Fire" and has 127 active volcanoes, according to the volcanology agency.
In recent weeks, North Sulawesi's Ruang volcano has erupted, spewing incandescent lava as lightning flashed from its crater.
The eruption prompted authorities to evacuate more than 12,000 people living on a nearby island.
In December last year, more than 20 people were killed after Marapi volcano, one of Sumatra's most active volcanoes, erupted and belched grey clouds of ash as high as 3km.
