Santiago:
Chile on Tuesday began the evacuation of some 2,200 people living near the Copahue volcano close to the border with Argentina despite a decrease in seismic activity.
The National Geology and Mining Service said that while volcanic activity had diminished, the rise of underground magma had likely passed a "point of no return" and warned of a possible explosive eruption.
Authorities have said all women and children living within a 25-kilometer (15-mile) radius of the volcano must leave but men may remain to care for their animals.
Another 800 people were cleared from homes on Argentina's side of the border on Monday, according to local officials.
So far, the volcano has only spewed gas, not ash. Chile also issued a red alert for the 2,965-meter (9,700 foot) Copahue last December, but an eruption did not follow.
The June 2011 eruption of Chile's Puyehue volcano periodically disrupted air travel in much of the southern cone of South America, and as far away as Australia, for months.