A New Zealander who is among hundreds of tourists stranded on Bali as the Mt Agung volcano erupts says it could be several days before he gets a flight home.
Airlines have been issued a "red warning" about the danger of volcanic ash in the skies close to Bali after Mount Agung emitted a thick plume of smoke reaching 4000m.
It is the second major emission from the Indonesian island volcano this week, and flights have been disrupted.
The red warning means an eruption is forecast to be imminent, with significant emission of ash likely.
The main airport at Denpasar remains open, but many airlines have been cancelling flights.
New Zealander Alex Chapman said he was stuck for at least another two to three days.
"We're supposed to leave Bali last night, Auckland-bound via Sydney, but that got cancelled. We were then postponed to 9.30 this morning local time, that got cancelled. We then got pushed back to 8pm local time, that has again be cancelled. we've now been told we're not leaving Bali until wednesday night.'
Travellers to and from the region have been urged to contact their airline or travel agent to find out the status of their flight.
Bali is a major tourist destination, although the main resorts of Kuta and Seminyak are about 70km from the volcano.
Authorities have begun distributing masks in some areas as ash falls.
The ash cloud is said to be moving eastward from Bali towards the island of Lombok, and the main international airport there has been closed entirely.
The information director of Indonesia's Disaster Mitigation Agency tweeted that volcanic ash rain had fallen on the Lombok city of Mataram.
"Tourism in Bali is still safe, except in the danger (zone) around Mount Agung," the agency said in a statement.
It told people within a 7.5km exclusion zone to "immediately evacuate" in an "orderly and calm manner".
Magma - molten rock - has now been detected close to the volcano's surface, said officials and volcanologists.
New Zealand vulcanologist Janine Krippner - a leading expert on Mt Agung - told Morning Report all the signs were that a larger eruption was imminent.
"What's happened now is that magma has actually reached the surface of the volcano, so right now we are seeing the surface manifestation of that in this ash plume, which has been ranging between 1000 and 6000 metres above the volcano.'
About 25,000 people are thought to still be in temporary shelters after more than 140,000 people fled earlier this year. Increased volcanic activity had prompted fears a major eruption was imminent.
Most of the islanders outside the immediate exclusion zone were ordered to return home at the end of September, and the mountain has been intermittently rumbling since.
According to official estimates, the holiday island lost tens of millions in tourism and productivity during the major evacuation.
Indonesia sits on the Pacific "Ring of Fire" where tectonic plates collide, causing frequent seismic and volcanic activity.
It is home to more than 130 active volcanoes. The last time Mount Agung erupted, in 1963, more than 1000 people died.