EUGENE, Ore. — The Alaska Volcano Observatory issued its highest alert level for aviation Tuesday, after a volcano erupted in the Aleutian Islands that reportedly sent ash thousands of feet into the air. The alert was downgraded hours later.

The observatory says pilots reported the Bogoslof volcano on Bogoslof Island briefly erupted about 4 p.m. Alaska time.

Pilots told the observatory that a volcanic ash cloud rose to 34,000 feet.

The observatory said satellite data show a short-lived explosion that drifted to the south.

In a report about 6 p.m., it said that the steam and ash cloud had mostly dissipated, and that it didn’t pose air-quality problems for local communities.

Three hours after that, the observatory said that the alert level had been downgraded a notch because activity had apparently subsided.

The volcano is located in the Bering Sea about 850 miles southwest of Anchorage.

Many flights between North America and Asia head over Alaska area, but are not affected at this time.