`Island` emerges in Indonesian volcano crater

An island that has emerged in the middle of the crater lake of Indonesia's Mount Kelut may have been effectively plugging the volcano but it could be dislodged, scientists warned Tuesday.

The peak in East Java, whose fertile slopes are populated by thousands of people, was put on high alert on October 16 but has not fully erupted, puzzling scientists who say it is impossible to predict what may happen next.

"The island was visually captured by our CCTV (closed-circuit television) on Sunday, with smoke now pluming up to one kilometre (half a mile) from it," volcanologist Saut Simatupang told AFP.