The lava dome on an erupting volcano in Alaska's Aleutian Islands chain is growing slowly but has not shown any explosive behavior that would generate ash plumes.
Stephen McNutt with the Alaska Volcano Observatory said Wednesday the Mount Cleveland volcano on an uninhabited island is emitting a light steam from the crater.
He says commercial airlines traveling over the area have been notified of the elevated alert level, which was raised last week.
There is no real-time seismic monitoring system at the volcano, located on Chuginadak Island about 940 miles southwest of Anchorage. The observatory is unable to track local earthquake activity related to volcanic unrest.
Cleveland last showed signs of unrest last summer, with a small ash emission and upper-flank lava flows.
This is a developing story. Check back for updates.