7 June 2011
Last updated at 22:38
Clouds of ash are continuing to spew from the Puyehue-Cordon Caulle volcanic range in Chile, which began erupting after a large earthquake at the weekend.
The ash cloud, so large it can be seen from space, has drifted across Argentina and towards Paraguay - the Argentine authorities had to close borders in some areas because of poor visibility.
The ash and rocks are coming from a three-mile (5km) long fissure in the mountain range, carpeting the area in a thick dust.
Some 4,000 people have been evacuated from rural communities near the volcanic range and are living in temporary shelters, along with their pets and belongings.
There are concerns that a heavy build-up of ash could clog waterways like the already silt-heavy Golgol river in Chile, leading to flash flooding.
By Tuesday, the thick smog had reached the Argentine capital of Buenos Aires, temporarily shutting down the city's busy international airport.
Scores of flights in Chile and Uruguay were cancelled, while Brazil suspended services to the affected regions.
The Argentine tourist resort of Bariloche has been blanketed with ash, making the water of Nahuel Huapi lake almost indistinguishable from the shoreline.
Vulcanologists say the eruption is so far moderate, but that the range could begin expelling lava in the coming days, possibly with little warning.
It is the most serious eruption on the volcanic chain since the area was hit by a massive earthquake in 1960.