Holidaymakers stranded for days in Bali when a volcanic ash cloud forced the closure of the island's main airport began checking in for flights Saturday after Indonesian authorities reopened the terminal.

Ngurah Rai International Airport had been closed since late Thursday as Mount Raung on Java spewed clouds of ash into the sky, grounding hundreds of flights during peak tourist season on the resort island.

But the airport was reopened by Indonesia's transport ministry on Saturday after the ash cloud drifted southwest, clearing the skies for take off.

Long lines quickly formed at the airport as passengers queued in the hope of their flights being rescheduled soon.

Trikora Harjo, the airport's general manager, said things were slowly returning to normal at the terminal, with passengers queueing up to check in and crews preparing planes for departures.

"It's a bit crowded, because of the cancellations," he told AFP.

"I think maybe after one day, or two days, things will become normal again."

Australian carrier Jetstar announced it would resume its Saturday flights between Bali and Perth, declaring it "safe to operate daylight services". National flag carrier Garuda also announced they were resuming domestic and international flights to and from the airport.

Virgin Australia has cancelled all flights Saturday, and will reassess the situation in the afternoon, while AirAsia cancelled or rescheduled nearly a dozen flights.

The closure of Bali's airport saw 330 flights cancelled Friday and chaotic scenes at the terminal as hundreds of holidaymakers milled about anxiously awaiting any news.

Large crowds formed both inside the terminal and outside on the lawns, with passengers sitting and sleeping on the floor as the hours dragged on.

The travel chaos came at a busy time in Bali, with many Australians visiting the island during the school break and millions of Indonesians setting off on holiday ahead of the Muslim celebration of Eid next week.

Some passengers, learning their flights could be delayed by days, hired private cars and buses to travel overland from Bali to other airports on the neighbouring island of Java.

Two domestic terminals on the island of Java, closer to Mount Raung, remain closed. Two other airports on the island of Lombok, east of Bali, were reopened Friday after being temporarily shut.

Ash cloud shifts

The decision to reopen Bali airport came after the ash cloud shifted away from the island, said forecaster Steph Bond from the Australian Bureau of Meteorology's Volcanic Ash Advisory Centre.

In a reprieve for travellers and airlines, the skies above Bali should remain clear over the weekend despite Mount Raung continuing to erupt smoke and ash high into the sky.

"At least for the next maybe three or four days, it (ash cloud) should remain to the south and away from the island of Bali," she told AFP.

But beyond that it becomes more difficult to say where the ash could move, she added, with Indonesian meteorologists warning there was no sign Mount Raung would ease up.

Authorities raised the alert status of Mount Raung, a 3,300-metre (10,800-foot) volcano, late last month to the second highest level after it began to spew lava and ash high into the air.

Air traffic is regularly disrupted by volcanic eruptions in Indonesia, which sits on a belt of seismic activity running around the basin of the Pacific Ocean and is home to the highest number of active volcanoes in the world, around 130.