Residents and tourists have been told to stay at least nine kilometers away from the volcano Mount Agung, as Indonesian authorities raised the alert level to category four, meaning an eruption is imminent.

According to the BBC, about 10,000 people have already been evacuated. Meanwhile, Australia’s Department of Foreign Affairs and Trade has issued a travel warning. Its latest post dated September 22 posted on its Smart Traveller website went: “Local authorities have temporarily suspended all outdoor activities such as hiking and camping activities in proximity to the crater. Monitor local media reports and follow the instructions of local authorities. An eruption of Mount Agung could impact air travel in the region. Contact your airline or tour operator to confirm travel plans.”

The country’s Consumer Protection has urged travelers going to Bali to purchase adequate travel insurance that will cover them if an eruption will occur.

The same publication said that Air Asia, Malindo/Batik Air, and Garuda will accept requests for refunds should travelers opt to cancel their flights.

Bali’s Ngurah Rai Airport is preparing an emergency operations center should an eruption occur.

The volcano’s last eruption was in 1963, which killed 1,100 people.