Computer glitch caused Jetstar delays

Jetstar has apologised for a computer problem that has caused major disruptions for thousands of passengers so close to Christmas.

The airline had an IT outage causing issues for flights from early this morning, with an estimated 70,000 passengers delayed for between one and three hours.

The problem has been identified and fixed but not before causing chaos on one of the busiest flying days of the year.

"It is a special time of year. We never want to disrupt our customers or delay our customers in any way," Jetstar CEO David Hall told reporters in Melbourne.

"Again I apologise and we are working hard to ensure they will get to their destination very quickly and as much as we can this afternoon."

The problem was caused by an overnight data storage issue that was resolved at 7.30am. But Jetstar had to process passengers manually, causing delays.

Mr Hall said the airline was working with Qantas to try to get all customers affected to destinations, and trying to ensure passengers with connecting flights made those.

"We have got a number of the flights this afternoon, (and) where capacity is available, we have moved them across to Qantas. We are proudly part of the Qantas group and they will help us," he said.

He said the cause had been identified and he hoped there would be no repeat of the issue.

Several Jetstar passengers took to Twitter to complain about the impact and lack of communication from Jetstar.