A flight on its way to Bali has had to return to Darwin midway due to an "engineering issue".
The fully booked Virgin flight VA91 left Melbourne bound for Denpasar on Friday morning before a scheduled stop in Darwin.
It then left Darwin International Airport just after 3pm.
However, the plane made a U-turn while flying over the Timor Sea approximately halfway between Darwin and Timor-Leste.
The aircraft landed back in Darwin just before 5pm on Friday.
A Virgin Australia spokesperson said the flight had to turn back because of an "engineering issue".
"Virgin Australia has sourced accommodation for all guests in Darwin tonight and is working to reschedule them on to a service to Denpasar tomorrow, 31 December," they said.
"The safety of our guests and our people is Virgin Australia's number one priority."
Passenger Taylor Meyer said customers were still in the dark as to what exactly happened.
"Now we've been told we have to get out baggage and we’ll be told what going on later on, so we still don't have any idea," he said.
He said he was worried about the financial implications of the delay.
"I was supposed to be in Bali, then supposed to be going to a resort tomorrow morning so I'm not too sure if that’s going to happen anymore," he said.
'It just becomes a financial issued really because you've just got to pay for it all again."
A Darwin Airport spokesperson said the passengers would be processed as a priority.
"Our operations team is prepared and ready to manage the arrival of the flight and processing of the aircraft and passengers will be streamlined."
This is the second time this week that a Bali flight has had to return to Australia, after a "miscommunication" saw a plane load of holiday-makers sent back to Melbourne on Tuesday night.