About 150 tourists and National Forest Service employees were evacuated from the surrounding Conguillio National Park, about 400 miles south of Santiago, and helicopters were prepared to pull out 53 others, said Chile's Emergency Bureau director, Carmen Fernandez.
Hundreds spent the night outside or in shelters in Melipeuco, a town of 5,000 near the Llaima volcano. Others fled to communities farther away.
"Buses and army trucks have already been sent and are ready in case a decision is made to order a massive evacuation in Melipeuco," Fernandez said, but that doesn't appear necessary yet despite television images showing thick smoke and lava flowing from the crater.
"There are no signs yet of an increased risk," Fernandez said. "There is some flow of lava, but not in a continued manner yet."
Bureau officials and vulcanologists were flying over the volcano to monitor the situation.
The 9,400-foot volcano last erupted in May, but has not had a major blast since 1994. It is one of the most active of Chile's dozens of volcanos.
