The eruption of Indonesian volcano Mount Anak Krakatau has spewed clouds of ash over parts of the island nation, halting flights in and out of Jakarta.
Here's what you need to know if you're planning on flying to or from the region.
Where is Mount Anak Krakatau?
It's on a small island in Indonesia, about halfway between the larger islands of Java and Sumatra.
The volcano is west of Indonesia's capital city Jakarta and its main airport, Soekarno-Hatta International Airport.
When did Mount Anak Krakatau erupt?
There have been signs of activity since Friday, Indonesia's Geological Agency said.
Mount Anak Krakatau erupted for 30 seconds early on Sunday morning, with a subsequent 16-second eruption about 3 hours later.
The most recent eruption was about 8:20pm on Sunday, local time.
"The probability of further eruptions in the coming periods remains high," Indonesia's volcano monitoring agency said on Monday.
Two ash clouds have been identified using satellite imagery, with one rising to about 6 kilometres high, drifting north-east over Jakarta, Banten, West Java and nearby waters.
A second cloud went higher than 15km, spreading over parts of Banten, Lampung and Bengkulu provinces, the southern Sunda Strait and sections of the Indian Ocean west of Sumatra.
No casualties were reported and no evacuation order was issued, however, volcanic ash spread across parts of Jakarta and Lampung province on Sumatra's southern tip.
Indonesia's disaster mitigation agency said there was no imminent risk of a tsunami.
By Sunday evening, eight airports had closed, with 1,558 flights cancelled.
Which flights are being impacted?
Most of the cancelled flights were in and out of Jakarta.
Flights between Bali and Australian airports have not been affected, Qantas has confirmed.
And the ABC understands no Virgin Australia flights between Bali and Australia have been impacted either.
Qantas says the following flights are affected by the eruption:
QF39
QF40
QF41
QF42
A Qantas spokesperson said the airline had contacted customers and was providing assistance.
Singapore Airlines, Malaysia Airlines, AirAsia and Lion Air Group also cancelled flights.
When will flights be running again?
"We cannot ascertain when this will end due to the dynamic weather," Transport Minister Dudy Purwagandhi said in a statement on Monday.
It's unclear how long it will take for flights to resume after the ash cloud clears.
"Our meteorologists and operations teams are closely monitoring conditions in and around Jakarta and any impact on our operations," a Qantas spokesperson said.
"Services will resume when conditions allow."
Can I get a refund?
That depends on which airline you're travelling with, so you'll need to check with them.
For example, Qantas is offering customers refunds, travel credits or date changes for people who were booked to fly in and out of Jakarta between September 5 and 9.
People wanting to change the date of their flights can do so for up to a week from the date of their original flight, subject to availability.
"In these situations, travellers should first contact their airline or travel agent to understand their options, including rebooking, alternative travel arrangements or available refunds," a spokesperson for the Insurance Council of Australia said.
Does travel insurance cover volcanic eruptions?
The Australian government's Smart Traveller website says most travel insurers cover natural disasters as long as travellers bought the policy before it became a "known event".
"Travel insurance policies can provide cover for unexpected events such as volcanic eruptions and ash clouds, but cover varies between insurers and policies," an Insurance Council of Australia spokesperson said.
"Travellers should check their Product Disclosure Statement (PDS) to understand what their policy covers and any exclusions that may apply."
Travellers may be able to claim for:
Additional accommodation
Meals
Transport expenses
Other costs incurred as a result of the disruption.
However, the spokesperson said the extent of cover would depend on the terms and conditions of the specific policy a traveller has taken out.
They said affected people should:
Contact their insurer as soon as possible
Follow any guidance the insurer provides
Keep receipts and records of any additional expenses they incur.
"Travellers should also monitor advice from airlines, travel providers and local authorities," they said.
