Colombia's Nevado del Huila volcano erupted in a shower of hot ash, prompting thousands of people to leave their homes on Tuesday.
The remote volcano, 150 miles southwest of Bogota, erupted shortly before midnight Monday and appeared less active at daybreak.
The extent of the eruption was not clear, but even minor eruptions could cause landslides and flooding by melting the snow and ice cap atop the 17,484-foot volcano, and authorities maintained a red alert for settlements near the volcano.
About 3,500 people were leaving or being evacuated from the villages of Belalcazar and Paez, which are susceptible to flooding of the Rio Paez, said Carlos Marquez, national director of the Red Cross, on radio Caracol.
Cesar Lopez, director of geologic services at the Colombian Institute of Geology and Mining, said that the volcano "is now more calm, but we will have to analyze whether to maintain the red alert."
Eruptions last year at the Nevado del Huila were its first on record since the mid-16th century.
The Nevado del Huila, which is topped with a crown of ice, is Colombia's third-highest peak.
The latest eruption was preceded by seismic rumblings starting on April 8.
In 1985, the town of Armero was wiped off the map and 25,000 people were killed when another volcano, the Nevado del Ruiz, exploded and set off a series of mudslides. It was Colombia's worst natural disaster.