A volcano erupted on Alaska's Aleutian Island chain, leading to an aviation warning.
The Alaska Volcano Observatory said the Bogoslof volcano erupted at 10:15 a.m. Saturday Alaska time, creating an ash cloud that rose to 5.6 miles above sea level.
The agency issued a red, or warning, alert to aviation because of the ash cloud.
Bogoslof has erupted periodically since mid-December.
Ash can harm and stop jet engines. Ash from southwest Alaska volcanos is a threat airliners operating between North America and Asia when a cloud rises above 20,000 feet.