Jakarta: Indonesian authorities raised the warning on Semeru volcano on the island of Java to the highest level on Sunday after an eruption spewed a column of ash high into the air.
The evacuation of people, which includes children and seniors, living near the volcano in East Java province had also begun with 93 residents so far evacuated to shelters, Indonesia's disaster mitigation agency, BNPB said in a statement.
The plume from the volcano reached a height of 50,000 feet (15 km), said Japan's Meteorology Agency, which was monitoring for the possibility of a tsunami there.
The eruption on the eastern part of Java, some 640 km (400 miles) east of the capital Jakarta, follows a series of earthquakes on the west of the island, including one last month that killed more than 300 people.
Indonesia's Center for Volcanology and Geological Hazard Mitigation, PVMBG, raised the level of volcanic activity to IV from III, its chief said in a text message.
With the raised alert level, authorities warned residents not to conduct any activities within 8 km (5 miles) of Semeru's eruption centre, adding hot ash clouds had reached as far as 11.8 miles (19km) from the centre of eruption.
PVMBG chief Hendra Gunawan said the agency saw the potential for a bigger supply of magma this year compared to previous eruptions in 2021 and 2020.
"Therefore Semeru's hot clouds could reach further (this year) and at that distance there are many residences," he said.
Around the same time last year, the eruption of Semeru, Java's tallest mountain, killed more than 50 people and left several missing, while thousands were displaced.
Some residents nearby have evacuated independently to safer buildings like mosques and schools, according to a statement from the regional government of Lumajang, where Semeru is located.
"Most of the roads have been closed since this morning. Now its raining volcanic ash and it has covered the view of the mountain," Bayu Deny Alfianto, a local volunteer told Reuters by phone.
Small eruptions were continuing and it was raining in the area, he said.
The volcano began erupting at 2:46 a.m. (1946 GMT on Saturday), BNPB, said in a statement. Videos posted on social media showed grey ash clouds in nearby areas.
With 142 volcanoes, Indonesia has the largest population globally living in close range to a volcano, including 8.6 million within 10 km (6 miles).
The deadly late-November quake that hit West Java's Cianjur was a shallow temblor of 5.6 magnitude. A much deeper quake on Saturday in Gurat of 6.1 magnitude sent people running from buildings but did not cause major damage.