Ash from a volcanic eruption in Chile grounded flights in neighboring Argentina, officials said Tuesday.
Airlines canceled most flights Tuesday at the Ezeiza International Airport in Buenos Aires, an official there said. Airports in several other cities are also affected, according to the state-run Telam news agency.
Smoke and ash shot more than six miles into the the sky when the Puyehue-Cordon Caulle volcano complex in southern Chile first erupted Saturday afternoon. Authorities evacuated about 3,500 people from the area, the state emergency office said.
The Patagonia region in southern Argentina was the most affected by the volcanic ash.
Cities that draw tourists, like Bariloche, San Martin de los Andes and others in the area canceled school and public activities.
Ash piled as high as 30 centimeters (about 1 foot) on highways through Patagonia. Local governments used machinery to clear the roads.
Chile is located on the so-called "Ring of Fire," an arc of volcanoes and fault lines circling the Pacific Basin that is prone to frequent earthquakes and volcanic eruptions. Chilean authorities had evacuated about 3,500 people from the area, the state emergency office said Monday.
"I ask all the population (in designated areas) to evacuate as soon as possible, because ... human life could be at risk," said Juan Andres Varas, regional governor of Los Rios, Chile.
In a statement posted on the Los Rios government's website Monday, he said volcanic material and potentially toxic gases were slowly advancing toward the nearby Nilahue Valley.
"Fortunately, the valley doesn't drop abruptly, so we have time to evacuate," he said. Schools in some cities and rural areas in neighboring Argentina were closed Monday, even as the volcanic activity appeared to have diminished, the state-run Telam news agency said.
Argentinian authorities told Telam the volcano's impact was difficult to predict.
"We still don't know, because it depends on the wind how it will continue. ... The recommendation to the population is that they stay inside," Eduardo Munos, municipal civil defense director in Junin de los Andes, Argentina, said Monday.