Several airlines have suspended flights between Singapore and the Indonesian capital of Jakarta because of the risk posed by volcanic ash from the deadly Mt Merapi eruption.
Mt Merapi, one of the world's most active volcanoes, has had two major eruptions since 26 October, which have killed up to 130 people.
The volcano in central Java has been producing thick clouds of ash and superheated gases in its biggest eruption in a century.
Airline officials say the ash is a safety threat and could damage aircraft.
Among the airlines to cancel flights were Singapore Airlines, Japan Airlines, Malaysia Airlines, Lufthansa, Cathay Pacific, Turkish Airlines, AirAsia and Tiger.
The ABC reports that Qantas has decided not to cancel any of its service to and from Jakarta.
Indonesia has already shut its international airport at Yogyakarta, with flights diverted to the nearby city of Solo.
Air New Zealand says it doesn't fly directly into Indonesia, and its flight paths through other parts of Asia are unaffected.
Dozens of victims who were killed by heat clouds are to be buried in a mass grave in Yogyakarta, a disaster management official says.
Many of the dead were from Argomulyo village, 18 kilometres from the crater, but the official said they cannot be buried at their village because it is within the 20km danger zone.
In addition to the loss of life, some 200,000 people have been evacuated from the area.
The numbers of evacuees increased on Friday after officials widened the danger zone from 15km to 20km.