Bali volcano alert raised to highest level

Mount Agung, Bali, Indonesia. [Photo: Courtesy]

Indonesian authorities have raised alarm over an imminent major eruption of Bali's Mount Agung, whose evacuation zone around the volcano has widened.

Indonesian experts have since raised a state of alert to its highest level.

Bali’s airport was closed for 24 hours from Monday morning, disrupting 445 flights and some 59,000 passengers, due to the eruption and the presence of volcanic ash from Agung, but local officials said the closure could be extended. This situation has left thousands stranded in the tourist hotspot.

Video footage shared by the disaster agency showed cold lava flows (lahar) at a number of locations on the mountainside. Lahar carrying mud and large boulders can destroy houses, bridges and roads in its path.

Officials have warned residents to stay away from rock and debris flows, which have been spotted flowing down from the mountain.

How close is it to a major eruption?

The National Board for Disaster Management raised the alert to level four from 06:00 local time (22:00 GMT Sunday), because of "the possibility and imminent risk of disaster".

The volcano was seen emitting "continuous ash puffs" occasionally accompanied by "explosive eruptions" and "weak booms" that could be heard 12km (7 miles) from the summit.

"The rays of fire are increasingly observed at night. This indicates the potential for a larger eruption is imminent,” read part of the statement.

Bali, famous for its surf, beaches and temples, attracted nearly 5 million visitors last year, and its international airport serves as a transport hub for the chain of islands in Indonesia’s eastern archipelago.

Tourism business has slumped in Bali since September when Agung’s volcanic tremors began to increase.