An Alaska volcano that has been active for nearly six months has erupted again.

The Alaska Volcano Observatory says Bogoslof (BOH-gohs-lawf) Volcano in the Aleutian Islands erupted at 2:16 p.m. Sunday and sent a cloud of ash at least 35,000 feet (10,668 meters) high. The eruption lasted 55 minutes.

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 (6,096 meters).

After the eruption, the Aviation Color Code was raised to red, the highest level.

The agency says a person on nearby Unalaska Island reports seeing a large white-gray mushroom cloud form over Bogoslof, with ash falling out to the west.

(AP)