Evacuations after Chile eruption
The National Service of Geology and Mining said the explosion that sparked the eruption also produced a column of gas 10km high.
“You can see the fire [in the volcano] and a plume of smoke, and there’s a strong smell of sulphur,” top Los Rios region official Juan Andres Varas told reporters.
The government, which earlier ordered the evacuation of 600 people, expanded that number to 3,500 people to be relocated to shelters in safe areas.
Authorities issued a red alert, the maximum warning level, for the area and a border crossing between Argentina and Chile was closed.
A cloud of ash could be seen in the town of Bariloche, Argentina, about 100km east of the volcano.
Carlos Hidalgo, the town’s communications secretary, said: “Ash was dumped like a snowstorm... The city is covered in grey ash.”
Located in the Andes mountains, Puyehue is 870km south of the capital Santiago.
Its last major eruption was in 1960, following a magnitude 9.5 earthquake.