ALEUTIAN ISLANDS -- The Aleutian Islands' two erupting volcanoes continued to blow off steam Thursday.

And, for the first time since it began erupting July 12, the Okmok volcano on Umnak Island showed signs of lava.

Satellite data Thursday showed a low-level thermal anomaly, which suggests the presence of lava at Okmok, scientists at the Alaska Volcano Observatory say. The 3,500-foot volcano, which is about 60 miles southwest of Dutch Harbor, was also putting out an intermittent ash plume.

Mount Cleveland, another 100 miles west, has been showing signs of lava for a couple of days. A strong thermal anomaly was seen Thursday near the volcano's 5,676-foot summit.

Cleveland, which began erupting Monday, is also putting out a low-level ash cloud, the observatory said.