Indonesia's Mount Sinabug has been placed on "red-alert" after spewing thick plumes of smoke mile into the skyline in a spectacular display.
Residents took footage of the clouds of smoke rising from the volcano's crater, in its latest level of activity since the 2014 eruption.
A Volcano Observatory Notice for Aviation has now placed Mount Sinabug on red-alert - the highest threat level - which generally means an eruption could occur.
Authorities have also enforced a no-go zone 5km from the crater, the agency said.
The volcano emitted the plumes of ash at around 4.28pm Jakarta time on Sunday, spokesperson for Indonesia's Mitigation and Disaster Agency (BNPB), Sutopo Purwo Nugroho said on Twitter .
No casualties were reported.
Locals living near the volcano were urged to wear masks when ash rains down, a spokesman of national disaster management agency Sutopo Purwo Nugroho said.
Mount Sinabug stands at 2,460-metre tall and is one of the most active volcanoes in Indonesia , located in Karo district of North Sumatra province.
The volcano last erupted in 2014, killing 16 people and forcing thousands more to be evacuated from their homes.
