Indonesian authorities raised the warning level for the Semeru volcano to its highest level on Sunday, Kompas TV reported, after the eruption threw a column of ash high into the air.

Evacuations have begun for people living near the volcano in East Java province, said Torikul Haq, lead regional administrator.

The plume from the volcano has reached a height of 15 kilometers, the Japan Meteorological Agency said, which is monitoring the possibility of a tsunami.

Indonesia's Volcanology and Geological Hazards Mitigation Center, PVMBG, upgraded the volcanic activity level to IV from III, Kompas TV reported.

The eruption in eastern Java, about 640 kilometers east of the capital Jakarta, followed a series of earthquakes in the west of the island, including one last month that killed more than 300 people.

"Most of the road accesses have been closed since this morning. Now its raining volcanic ash and it has covered the view of the mountain," local volunteer Bayu Deny Alfianto told Reuters by telephone.

As the alert level increased, authorities warned residents not to conduct any activities within an 8-kilometer radius of the center of the eruption Semeru, Kompas TV reported.

The volcano began erupting at 02:46 local time, the Indonesian disaster mitigation agency BNPB said in a statement. Videos posted on social media show gray ash clouds in nearby areas.

Indonesia has 142 volcanoes and has the world's largest population living in close proximity to a volcano, including 8.6 million people within a 10-kilometer radius.