SANTIAGO (BNO NEWS) -- The Chilean government on late Wednesday afternoon declared a Red Alert for the country's Aysén region after a significant increase in seismic activity at Mount Hudson, forcing nearly 100 people to evacuate.

The National Office of Emergency of Chile's Interior Ministry (ONEMI) initially declared a Yellow Alert for the area, but later raised it to Red after seismic activity continued to increase. It ordered about 100 people in a radius of 40 kilometers (24.8 miles) to evacuate.

Interior Minister Rodrigo Hinzpeter said the decision was taken after regional authorities and scientists flew over the volcano, noting that a column of white gas and some ash with a height of about 1.5 kilometer (0.9 mile) was visible. No lava was visible, but authorities pointed out there was a subglacial eruption in 1973.

The Chilean government warned it could not rule out the possibility of a major eruption within hours or days. Hinzpeter added that a Committee for Regional Emergency Operations has been formed and will begin evacuating the 97 people, who are located in the sectors of Cajón Bravo, Las Malvas, El Salto and Cupquelán. He called on the population to remain calm and stressed that the evacuation is a precautionary measure.

Volcanic eruptions at Mount Hudson are characterized by eruptive columns several kilometers (miles) high, which could affect localities around the volcano. But unlike most volcanoes in other regions of Chile, Aysen population centers are situated downwind of volcanic centers and therefore are highly likely to receive pyroclastic material, ONEMI said.

The emergency office added that lahar could affect the valleys near the Huemules and Cupquelán rivers, located northwest of the volcano. In addition, pyroclastic flows could affect the areas located 15-20 kilometers (9.3-12.4 miles) away from the volcano, depending on the scale of the eruption.

Wednesday's measures follow a Preventive Early Warning issued on June 14. Mount Hudson experienced moderate eruptions in 1891 and 1971, followed by a 'colossal' eruption in 1991 which reached 5 on the 8-step Volcanic Explosivity Index. There were no casualties due to the remoteness of the area.

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