A red alert has been issued in Chile after a volcano started spewing ash and gas on Saturday.

Chile’s emergency office Onemi raised the alert after a mile-high cloud of ash billowed out of the Copahue volcano.

The volcano lies on the border with Argentina, and south of the capital Santiago.

Officials say there was no need yet to evacuate.

“Authorities have overflown the volcano area and the alert is still red,” Gilda Grandon, from Onemi’s BioBio unit was reported as saying by Sky News.

“We have noted some drop in the ash plume but the alert level is maintained because a full eruption is not ruled out.”

The 2,967m-high Copahue last erupted in 1991. Twenty years later it became highly active with blasts and gases.

A volcano in the Caulle Cordon of southern Chile erupted violently last year, forcing the cancellation of hundreds of flights and the evacuation of more than 3,500 people.