(AP) -- One of the volcanos in the Caulle Cordon of southern Chile erupted violently Saturday, billowing smoke and ash high into the sky and prompting more than 3,500 people living nearby to evacuate.
There were no reports of injuries.
Authorities initially said the Puyehue volcano was involved, but later said the eruption was occurring about 2 1/2 miles (four kilometers) from that peak.
A rift more than six miles (10 kilometers) long and three miles (five kilometers) across was torn in the earth's crust, officials said Saturday night.
Authorities had put the area on alert Saturday morning after a flurry of earthquakes, and the eruption began in the afternoon. The National Emergency Office said it recorded an average of 230 tremors an hour.
About 600 people were evacuated when the first alert went up and hundreds more left their homes after the eruption began.
Rodrigo Ubilla, Chile's undersecretary of labor, said some people near the volcano had decided not to leave their homes because they didn't want to abandon their animals.
Wind carried ash across the Andes to the Argentine tourist town of San Carlos de Bariloche, which had to close its airport.
Officials warned residents of the Bariloche area to take precautions against a possible prolonged ashfall. They urged people to stock up on food and water and to stay home.
The eruption is nearly 620 miles (1,000 kilometers) south of Chile's national capital, Santiago.
Explore further: Lightning plus volcanic ash make glass