Thousands of people on Lembata Island in Indonesia's Solor Archipelago are sleeping away from home as Mount Batutara spews ash and lava.

The volcano became more active Saturday, the Jakarta Post reported. Tons of ash and lava spewed from its cone into the sea.

"The mountain's increasing activity forced 15,700 residents of the Buyasuri and Omesuri districts to evacuate at night and return home in the morning," Lembata deputy regent Andreas Duli Liliweri said.

Scientists from the geological mitigation office were unable to get close to the volcano because of rough seas, Liliweri said, forcing them to monitor its activity from more than a quarter mile away.