Airlines offering flights from New Zealand to Indonesia are keeping a close eye on a cloud of ash 17km high created by the latest eruption of Mt Kelud on the island of Java.
Three people have been killed and up to 200,000 people ordered to evacuate following the eruption of Mt Kelud in eastern Java on Thursday night.
Airports in the cities of Surabaya, Yogyakarta and Solo are closed. Authorities said airports in Malang, Cilacap and Semarang reopened on Saturday.
Some flights from Australia were delayed on Friday, but none from New Zealand are so far affected.
The CAA said only planes flying directly to or from Indonesia are affected so far.
Chief meteorological officer Peter Lechner said others will chart a different route to avoid the ash cloud.
Mount Kelud (1731 metres) is one of 130 active volcanoes in Indonesia. It last erupted in 1990. Another eruption in 1919 killed around 5000. About 10,000 died in a massive eruption in 1568.