Chilean authorities are downgrading the likelihood of another big eruption from the Calbuco volcano, although the mountain remains active and the ash clouds it already ejected have caused cancelations of more airline flights.

The head of the National Mining and Geology Service says Calbuco's seismic activity has changed. Rodrigo Alvarez says the volcano will stay active for a while longer but officials no longer expect a third strong eruption like those on Wednesday and Thursday.

A few airline flights were cancelled Saturday as volcanic ash spread over more of the southern half of South America.

At the foot of the volcano, Chilean authorities allowed some of the 1,500 people who evacuated the town of Ensenada to return temporarily to their homes to clean up damage from the heavy ash fall.