Some 122,000 people have been evacuated in view of a possible eruption of Mount Agung, a large volcano on the Indonesian island of Bali, authorities announced on Thursday.
The authorities have set up a 12-km radius exclusion zone around the volcano, reports Efe news.
According to latest figures, however, 62,000 people were still within the exclusion zone.
The Centre for Volcanology and Geological Hazard Mitigation (BNPB) raised the alert level to a maximum 4 on September 22 and has been recording a constant increase in activity through volcanic movements, thermal energy and the volume of the volcano.
On Wednesday, the authorities had also installed mobile sirens to warn residents of a possible eruption.
Experts have said that it was impossible to predict if the 3,031-metre-high volcano will erupt or not.
A plan has been drawn up to redirect air traffic to other airports in case of an eruption.
The BNPB had said in a statement on September 21 that the current tremors were similar to those that occurred before Mount Agung erupted in 1963, which lasted almost a year and killed over 1,100 people.
Indonesia is home to more than 400 volcanoes, of which at least 127 are active and 65 are classified as dangerous.