Some living near the rumbling mountain reported hearing “strong, strange noises” coming from the summit of the 17,457-foot mountain.
About 150 families were evacuated from the banks of rivers and streams that have their source on the volcano’s slopes.
This was to prevent the kind of disaster that killed more than 25,000 people in 1985 when lava melted Nevado del Ruiz’s snowpack, sending a huge surge of water and debris downstream.
The flash flooding virtually obliterated communities along some of those streams.
The area around the volcano remains on an orange alert, the second highest, meaning dangerous activity is likely to continue for days or even weeks.
The local La Nubia airport was closed for an indefinite period of time due to the hazard ash poses to aircraft.
Photo: Instituto Colombiano de Geología y Mineria