Flights from Australia to Bali were cancelled on Saturday night as a massive volcanic ash cloud from Indonesia sweeping across Australia threatens to disrupt air travel for days.
The eruption of the Sangeang Api volcano on Friday night caused the cancellation of Australian flights to Darwin on Saturday and to Denpasar on Saturday night.
The ash plume shut down Darwin International Airport on Saturday, before moving into Western Australia and grounding planes at East Kimberley Regional Airport.
Deputy Prime Minister Warren Truss warned more airports around Australia could be affected as authorities monitored three separate ash plumes.
"Depending on wind and other weather conditions, the ash has the potential to affect flights to and from other airports, including Brisbane, during coming days," he said.
"This is currently being fully assessed."
On Saturday, Qantas, Jet Star and Virgin Australia all cancelled flights from Sydney to Darwin. A Jetstar and a Virgin Australia flight from Sydney both made it through to Bali earlier in the day, while the airlines did not have flights from Sydney to Denpasar scheduled in Saturday evening.
Jetstar has already cancelled its Cairns to Darwin return service on Sunday morning. Other airlines have not yet announced what, if any, flights would be stopped but have directed travellers to monitor their websites for news.
"Our team of meteorologists are continuing to monitor the situation, in consultation with the Volcanic Ash Advisory Centre," Virgin Australia spokeswoman Jacqui Abbott said.
The first ash cloud, between 20,000 and 50,000 feet high and up to 15 kilometres across, was tracking south-easterly over central Australia on Saturday night about 100 knots but dissipating quickly.
A second cloud at about 45,000 feet was over Darwin and moving east about 60 knots.
The third ash cloud, north-east of Bali, is not expected to enter Australian airspace.
Virgin flights VA51 from Melbourne to Denpasar and VA33 from Adelaide to Denpasar were cancelled.
Melbourne man Jesse Hogan said people were in shock after their 3.40pm flight was cancelled, leaving them stranded at Melbourne Airport.
"I got through Customs and everything a breeze and it was only about half an hour before the flight was about to go, when we were due to board, when we heard the flight was cancelled," he said.
"We're sort of stuck in here in limbo."
Qantas spokeswoman Kira Reed said all flights to and from Darwin were cancelled on Saturday, and Jetstar and Jetstar Asia flights had been cancelled to and from Bali and Singapore.
"Jetstar will continue monitoring the situation throughout the day and will update affected passengers if further cancellations are to come this evening," she said.
Darwin woman Mandy Hall was in Hobart on Saturday anxiously waiting to see if she could fly to Melbourne with Jetstar on Sunday.
"I don't think that our flight will be leaving from Melbourne tomorrow to get back to Darwin," she said.
"From what I've learnt about volcanic ash, it's not something that's going to disappear overnight."
The Bureau of Meteorology's Volcanic Ash Advisory Centre and Civil Aviation Safety Authority (CASA) are closely monitoring the ash plume.
CASA has issued a warning to Australian pilots and aviation operators of the hazards of flying through or near the dust but each airline makes its own decisions under the international system.
CASA spokesman Peter Gibson said the ash could affect large and small aircraft with piston and turbine engines.
"Volcanic ash clouds contain extremely fine particles of pulverised rock made up mainly of silica," he said.
"The silica is very hard and abrasive and can be very damaging to aircraft structures, engines and windows.
"The silica can also melt inside jet engines and be deposited in the hot sections of engines."
Tim Birch, a meteorologist from Darwin Volcanic Ash Advisory Centre, said predictions could not be made about how long the ash cloud would continue to affect air travel to and from Darwin.
"It is entirely dependent upon what happens with the volcano."
Mr Birch said that, based on the current weather conditions and volcanic action, Australia's eastern ports including Sydney and Brisbane would remain unaffected.
Sangeang Api's first recorded eruption was in 1512 and it last erupted in December 2012.
The most recent eruption has forced the evacuation of farmers from areas on the slope of the volcano.
- with Melanie Kembrey