Volcano Galeras, Nariño department in South-West Colombia, is likely to erupt again in the next days or weeks, the Colombian Institute of Geology and Mining (Ingeominas) warned Tuesday.
Ingeominas changed the level of activity from yellow to orange II.
The inhabitants of the danger zone are advised to be attentive to instructions from local authorities.
The most recent eruption of Galeras was last April 25. No one got injured but it caused fear among the inhabitants of Pasto, the capital of Nariño department.
Volcano Galeras, with a height of 4275 meters above sea level, reactivated in 2004 and has since then recorded several eruptions.