The alert level for Cleveland Volcano has been raised again after scientists found another lava dome has formed in the crater in the last week.
The Alaska Volcano Observatory on Wednesday increased the level for the volcano, a 5,675-foot peak on uninhabited Chuginadak Island about 940 miles southwest of Anchorage in the Aleutians.
The status was raised earlier this year when the center detected two small, likely ash-poor eruptions through March 13, but lowered the alert level last week after 10 days of inactivity.
Scientists can't actively monitor the volcano because there is no real-time seismic monitoring network on the volcano in the Aleutian Islands.
Authorities say sudden eruptions could occur at any time, and ash clouds 20,000 feet above sea level are possible.