BOGOTA , Colombia ( CNN ) -- Colombian emergency officials have begun evacuating 800 families from an area at high risk from the expected eruption of a volcano that killed at least six people in November . Colombians make their way across a landslide in November after the Nevado del Huila volcano erupted . The Nevado del Huila volcano is on orange alert , meaning an eruption is probable within days or weeks , the Colombian Institute of Geology and Mining said last week . An eruption would cause an avalanche down the Paez and Simbola rivers , officials said . The town under evacuation , Belalcazar , sits on the bank of the Paez River about a half-mile ( less than a kilometer ) from the junction with the Simbola River . It was the worst-hit area in November 's eruption . The volcano 's crater holds 52 million cubic meters ( 1.8 billion cubic feet ) of lava , said Colombia 's Caracol Radio . That 's the equivalent of 13.8 billion gallons . The Colombian national emergency agency said Monday it is ready to evacuate thousands of residents if the volcano 's condition turns to red , which means an eruption is imminent or ongoing . The snow-capped Huila , the highest active volcano in Colombia , last erupted on November 20 . At least six people , including four children , died then . Gas and hot ash caused snow on the mountain peak to melt , sending mud , rocks and floodwater rushing down the Paez and destroying at least 20 homes and washing out five bridges , the presidential office said at the time . Much of the sparsely populated region about 155 miles ( 250 kilometers ) southwest of Bogota is a reservation for Nasa indigenous communities . All six fatalities were native Indians , the government said . The youngest victim was a year old . The Huila volcano , which has a summit of 17,598 feet ( 5,364 meters ) , has erupted four times . The first documented eruption occurred in the 1500s , then it stood silent for more than 400 years , according to the Web site volcanolive.com . Colombian emergency officials said Monday they are asking the 800 families where they want to be moved to , Caracol Radio said . Scientists with the Colombian Institute of Geology and Mining , commonly known as Ingeominas , said they did not detect any major action inside the volcano Monday , Caracol reported . Ingeominas and the National System for Emergencies are monitoring the volcano around the clock and have acquired new equipment , including additional telecommunication gear and an infrared camera to monitor Huila 's temperature . Officials also plan to install a microphone on Huila to detect any new rumblings from inside the volcano , Caracol said . Officials already are monitoring the volcano with four stations that detect seismological activity , a video camera , a communications network and a system that measures mudflow , Caracol said .
Eruption likely within days or days at Nevado del Huila volcano , agency warns . Simbola volcano 's eruption killed Some 800 people in days . Some 800 families under evacuation from high-risk area . Eruption would cause avalanche down Paez and Simbola rivers , officials say .