Warned that an increasingly active volcano could erupt any time, the number of people taking shelter in makeshift evacuation centers on the Indonesian island of Bali has surged to around 104,000, officials said yesterday.

Spewing white smoke and sending tremors through the area, Mount Agung's alert status was raised to the highest level last week. Since then, tens of thousands of villagers have been urged to abandon their homes beneath the menacing volcano. The national disaster management agency has housed evacuees in tents, school gyms, and government buildings in neighboring villages.

While there are plentiful stocks of food, water, medicines, and other supplies, evacuees fear they are in for a long wait that could disrupt their livelihoods.

One farmer said he was worried that lava flows could destroy his house and farm. Officials also noted there are around 30,000 cattle within the danger zone around the volcano, and efforts are being made to move the livestock as it is an important source of income for many residents. More than 1,000 people were killed the last time Mount Agung erupted, in 1963. An elderly woman who survived that eruption said evacuation instructions had come much earlier this time.

"Back then we weren't evacuated until it got really dangerous. Life went on as normal when ash and gravel was falling on us, until the big lava came out and destroyed everything," said 82-year-old Gusti Ayu Wati.

Indonesia has nearly 130 active volcanoes, more than any other country. Many of these show high levels of activity but it can be weeks or even months before an actual eruption. Bali is famous for its beaches and temples and saw nearly 5 million visitors last year, mainly from China, Australia, and Japan.

Bali's tourism department yesterday issued a letter reassuring travellers, and noting that flights were operating normally. Ash clouds from volcanic eruptions have disrupted tourism in Bali and other parts of Indonesia in recent years. Hundreds of domestic and international flights were disrupted in 2016 when a volcano erupted on Bali's neighboring Lombok island, sending columns of ash and debris into the air.