More than 20,000 Australians expected to fly to Bali in the next two weeks could be left stranded on the island if the Mount Agung volcano, which is on high alert, erupts.
Tremors in the region are increasing and warnings have been raised to the maximum level four, with an eruption believed to be imminent, but airlines say flights to Bali are continuing in the meantime.
An increased number of families are expected to travel to the popular travel destination, with school holidays now underway in NSW, Victoria, Queensland, Western Australia and the ACT, and commencing next week for schools in South Australia, Tasmania and the Northern Territory.
A spokesman for Jetsar said the airline runs 60 direct flights to Bali from major Australian cities every week, transporting more than 10,000 passengers.
He said all services were running as scheduled, but the airline was "keeping a close watch on the situation".
A spokeswoman for Qantas said its "team of meteorologists are continuing to monitor volcanic activity".
"They're saying it's imminent but that could mean a week," she said. "Our operations team will provide an update when we know more."
A spokeswoman for Virgin Australia also said flights were continuing as scheduled, and the airline would continue to update passengers on the situation.
The Australian Department of Foreign Affairs has issued updated advice to travellers warning that an eruption "could impact air travel in the region".
"Contact your airline or tour operator to confirm travel plans," the department has advised.
About 240,000 people are fleeing the region surrounding the volcano, which last erupted in 1963, when it killed 1100 people. There are reports monkeys and snakes are also leaving the mountain.
Mount Agung is 71 kilometres from the tourist city Kuta, and about 76 kilometres from Denpasar Airport, but any volcanic ash could impact flights in and out of the region.
A number of flights to and from Bali were grounded during the September school holidays last year when Mount Rinjani, an active volcano nearly 250 kilometres from the airport, began erupting volcanic ash.
Flights were disrupted for nearly a week due to an ash cloud from Mount Rinjani in November 2015.