Thousands of Australians hoping to holiday on the Indonesian island of Bali have had their plans disrupted by flight cancellations following volcanic activity on neighbouring Java island.

Jetstar spokesman Simon Westaway said on Friday: “We have to take a safety first approach. The complexity is that while visibility can come and go, there is volcanic ash in the vicinity of Denpasar airport.”

Jetstar is the budget subsidiary of Quantas Airways, which itself does not fly to Bali.

Jetstar and rival Virgin Blue on Thursday cancelled flights to Bali from Sydney, Melbourne, Darwin and Perth because of the ash cloud over Denpasar's Ngurah Rai Airport.

Virgin Blue said a temporary ban had been placed on all flights to and from Bali.

“This decision has been made based on advice from the Darwin Volcanic Ash Advisory Centre,” the airline's website said.

The centre, in the far-north city of Darwin, is part of Australia's Bureau of Meteorology.

It said the Tengger Caldera had erupted. The caldera includes Mount Bromo, which lies within the Bromo-Tengger-Semeru National Park.

- Sapa-dpa