Flights resume after ash cloud shifts

Jetstar has resumed flying to and from Bali while Virgin Australia flights are now running on time, after a volcanic ash cloud hovering around Denpasar airport moved away from the area.

"We've determined it's safe to resume services," Jetstar said in a statement on Thursday.

Virgin Australia agreed, saying all of its day-time flights from Australian to Denpasar will operate.

The airline will update travellers at about 2pm AEST on the fate of its evening services from Denpasar.

"We are monitoring the situation closely," Virgin Australian said.

Unfavourable winds this week pushed ash from the Mount Raung volcano in Indonesia back towards Denpasar, forcing the closure of its airport.

Ash clouds can choke jet engines and destroy bodywork.

Aviation expert Geoff Thomas says while the winds are blowing the ash cloud away from Bali, the threat may not be over.

"This volcano is continuing to erupt," he told the Seven Network.

"It shows no sign of abating and it really depends on the wind conditions, which way the wind is going to blow this ash, and so we could have the same situation in 24 or 48 hours."

Both airlines will operate additional flight in and out of Denpasar to help travellers get to their destinations.

Virgin Australia also said it would waive fare differences for travellers booked to travel to Bali by July 28, but who want to switch to one of 12 other Indonesian islands.

Earlier this month, thousands of Australians were stranded for extended periods in Bali due the threat of the ash cloud.