A Jetstar flight from Sydney to Phuket was diverted to Bali after a brawl broke out, reports said.

Six rowdy Australian men were escorted off flight JQ27 and five were taken into custody on the Indonesian resort island, Australian media reported on Wednesday.

The men arrested were Bradley Beecham, Brett Eldridge, Mark Rossiter, Ricky William and Lynmin Waharai, said News Corp Australia. Michael Matthews, believed to be the victim of the attack, is also in Bali.

They were believed to be drunk.

The fight broke out about three hours into the flight, which took off at 2.25pm, reports said.

"A group of six passengers travelling together were being extremely disruptive amongst themselves and refused requests from our crew," ABC said, quoting a Jetstar spokesperson.

"The captain decided to divert the flight to Bali where Indonesian police took the disruptive passengers off the aircraft. The flight then continued without incident to Phuket."

Jetstar added that "the other customers onboard supported the decision to offload the group in Bali and thanked the crew".

The flight was delayed by about two hours, but the other 309 passengers continued to Phuket, landing after 11pm.

Passengers said the men were extremely disruptive.

"Love it when a fight breaks out over your seat. Thank you Jetstar for handling the situation really well considering how bad they were," said a passenger on Facebook.

Megan Wilson, who said she had three friends on the flight, commented on Facebook that "blood was everywhere".

She said her friend was in tears and kids were screaming, calling it "a massive punch up".

Head of Ngurah Rai Airport Authority, Yusfandri Gona, told the Sydney Morning Herald that the men will be sent back to Australia on separate flights from Thursday evening.

The case will be handed over to the Australian police, he said.