AFP/ Denpasar

An erupting Indonesian volcano forced the closure of five airports Friday, including on the holiday island of Bali, causing about 350 flights to be cancelled and stranding thousands of holidaymakers.

The international airport on popular Lombok island was also among those closed late Thursday as Mount Raung on the main island of Java spewed clouds of ash, the transport ministry said.

The closures came during peak holiday season in Bali, a pocket of Hinduism in Muslim-majority Indonesia which attracts millions of foreign tourists every year to its palm-fringed beaches.

"It's pretty chaotic," Katie Nagar, an American expatriate living in Indonesia told AFP. She described arriving at the domestic terminal in Bali's Ngurah Rai airport to discover her flight to Jakarta on Indonesian flag carrier Garuda had been cancelled and rescheduled to Sunday.

"There's basically just hundreds of people camped out on the grassy lawns in front of the airport. There's lines of hundreds of people waiting to talk to customer service."

An AFP reporter in the international terminal estimated about 1,000 people were stranded there, with some trying to seek information from airport officials while others were sitting or sleeping on the floor.

Trikora Harjo, general manager at Ngurah Rai, said that 330 flights -- 160 domestic and 170 international -- had so far been cancelled at the airport due to the ash cloud.

"Right now the authorities have declared that the airport will be closed until 9:30 pm (1330 GMT), totally closed," he said.

Garuda said it had cancelled a total of 112 flights Friday. Most were to and from Bali airport, but 18 were to other airports affected by the ash cloud. AirAsia, Virgin Australia, Jetstar, and Air New Zealand also confirmed flights to Bali had been cancelled.

The disruption came as many Australians were in Bali for the school break, and many Indonesians were setting off on holiday ahead of the Muslim celebration of Eid next week.

- Emitting flames -

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.

Government vulcanologist Surono, who like many Indonesians goes by one name, said eruptions were continuing at the volcano Friday, and it was producing flames and a thundering sound. But authorities said no evacuations were necessary as those living in the area were already a safe distance away.

Virgin Australia said in a statement that "our team of meteorologists continue to work closely with the Volcanic Ash Advisory Centre in Darwin and monitor the situation.

"Once conditions improve, additional flights will be scheduled between Australia and Denpasar to ensure we can have guests on their way as soon as possible."

Jetstar also grounded its services and asked passengers to contact it for further information.

The two Australian carriers had already cancelled flights in and out of Bali in recent days due to the volcanic ash, even before the airport was fully closed.

Air New Zealand said a flight due to depart from Bali on Saturday afternoon was rescheduled, while AirAsia axed services from Bali and neighbouring Lombok to Indonesian and international destinations, including in Australia, Malaysia and Taiwan.

Other airports closed by the ash included a second, smaller one on Lombok and two in East Java serving domestic routes.

Indonesia sits on the Pacific Ring of Fire, a belt of seismic activity running around the basin of the Pacific Ocean, and has around 130 active volcanoes.