As the school holidays enter full swing, thousands of Australian families ready to fly to Bali could be left stranded under the threat of a volcanic eruption as Bali locals flee their homes and brace for a natural disaster.

Indonesia has warned a volcanic eruption may be imminent at the Mount Agung volcano, situated about 72 kilometres to the northeast of the tourist hotspot of Kuta.

The last time Mount Agung erupted in 1963, it killed about 110 people and hurled ash as high as 10 kilometres.

The Australian Department of Foreign Affairs and Trade on Friday issued official advice to “exercise a high degree of caution” if travelling to Indonesia, including the popular tourist island of Bali.

“An eruption of Mount Agung could impact air travel in the region,” the ADFAT said. “Contact your airline or tour operator to confirm travel plans.”

It also advised Australians to monitor Indonesian media and follow the instructions of local authorities.

Tens of thousands of villagers in the Karangaasem district in east Bali have already fled their homes, with Indonesia warning the active volcano could erupt at any moment.

Local authorities have temporarily suspended all outdoor activity such as hiking and camping activities in proximity to the Mount Agung crater.

It is the third time in little more than a week that the alert level was raised.

School holidays have begun in Victoria, New South Wales, Queensland, Western Australian and the Australian Capital Terrirtory, with many travellers planning to visit the tourist island during the next two weeks.

South Australia, Tasmania and the Northern Territory will observe holidays next week.

A Qantas spokesperson told The New Daily the Australian airline was “closely monitoring the activity of Mount Agung”.

“But there is no impact to our services at this stage,” the spokesperson said, adding the airline offered one outbound flight to Bali each week.

Flights at Bali’s international airport are operating as usual, with little disruption to tourism operators across the surrounding Indonesian island.

Australian tourists have taken to social media to express their disappointment about planned trips or concern if already vacationing in the region.

https://twitter.com/masonxd1/status/911345988480020480

https://twitter.com/DomKoudsi/status/911385159156473856

#BaliVolcano I'm traveling to Bali with a group of doctors tonight. Can anybody give me an update regarding the situation there!

— DOKERIC (@Dokeric) September 23, 2017

Earlier this week, Insurance company Travel Insurance Direct issued  a statement outlining changes in cut-off time for its various policies in anticipation of increased claims.

“With the volcanic activity at Mount Agung, Bali, Indonesia increasing significantly and with recent extension of the evacuation zone around the volcano by Indonesian officials, we are now issuing a cover cut-off time in anticipation of travel and other services being impacted,” it said.

“For policies purchased after 4pm (AEST) on Wednesday 20 September 2017, cover is not available for claims arising from any volcanic activity, including any new ash cloud events, as such events are no longer unforeseen.”

The Department of Meteorology, Climate and Geophysics said there has been a “tremendous increase” in the mountain’s seismic activity, indicating a greater probability of an eruption, though it couldn’t give a timeframe.

The National Disaster Mitigation Agency said no residents or tourists should be within within 12km of the crater to the north, northeast, southeast and south-southwest.

Waskita Sutadewa, a spokesman for the disaster mitigation agency in Karangasem district, said nearly 11,300 villagers have been officially evacuated.

He said the real number of displaced might be two or three times that, since many have voluntarily fled their homes.

The agency says evacuees are staying in temporary shelters, sports centres, village halls and with relatives.

– with AAP