Twin blasts from the Calbuco volcano in southern Chile have sent vast clouds of ash into the sky, increasing concerns that it could contaminate water, cause respiratory illnesses and ground flights.
The volcano erupted Wednesday afternoon for the first time in more than four decades, then had another outburst early Thursday.
Authorities have evacuated 4,000 people and closed access to the area around the volcano, which lies near the cities of Puerto Varas and Puerto Montt, some 1,000 kilometers south of Santiago.
LATAM airlines cancelled flights to and from both cities because airborne ash can damage jet engines.
No injuries are reported but one hiker remains missing.
President Michelle Bachelet issued a state of emergency and is expected to visit the area.