Chile volcano: Ash cloud forces flight cancellations
A cloud of ash spewed from a volcano range in Chile has grounded flights at airports in Argentina and Uruguay.
All flights from the Argentine capital Buenos Aires and many from Montevideo, in Uruguay, have been cancelled.
Chile's Puyehue-Cordon-Caulle volcano range, about 800km (500 miles) south of Santiago, began erupting last Friday.
An airport official said that the cloud was now directly above Buenos Aires, at a height of 9,000m (29,000ft).
Other smaller airports in Argentina will also be closed, officials say, and a crisis committee is due to meet to re-evaluate the situation later.
"All flights have been cancelled because the ash cloud is above Buenos Aires," a spokesperson for Aeropuertos Argentinos 2000, the group that manages the area airports, told Agence France Presse.
The official said that the ash cloud was just beneath the height at which planes normally fly.
In Uruguay, many flights into Montevideo's Carrasco airport were also cancelled.
After being cancelled earlier in the week, flights into Buenos Aires - a key air hub for the whole of South America - had begun to resume on Wednesday.
Changing wind directions have pushed the ash cloud back and forth across southern Argentina and Chile.
This is the first serious eruption of the volcano chain since 1960, when the area was hit by a massive earthquake.
Chile is one of the most volcanic countries on Earth. There are more than 3,000 volcanoes dotted along its length, and around 80 of them are active.