The fishing boat Tara Gaila picked up the seven adults and three children from Umnak Island after the group called military police on Kodiak Island and requested help, the Coast Guard said in a statement.

The call for help came about 15 minutes after the Okmak volcano erupted unexpectedly, sending a cloud of ash some 35,000 feet into the sky.

The ash was thick enough that a Coast Guard helicopter that had been dispatched to Umnak Island was forced to land in the fishing town of Dutch Harbor.

The Alaska Volcano Observatory said in an advisory that ash in the Dutch Harbor area continued to pose a threat to aircraft.

The observatory said the volcano is about 65 miles from Dutch Harbor and last erupted in 1997. It was not immediately known if the explosive eruption produced a lava flow.