Days after regional airline Rex revealed it was withdrawing from bushfire-ravaged Kangaroo Island, Qantas has announced plans to double its number of services to the popular tourist destination.

Key points: Qantas said it was stepping in to fill the void left by Rex

Qantas said it was stepping in to fill the void left by Rex The number of QantasLink's weekly services will increase from five to 12

The number of QantasLink's weekly services will increase from five to 12 The airlines have entered a war of words over the outcome

QantasLink announced it would increase weekly flights to and from Kangaroo Island by July, as well as release a revised schedule.

Rex's decision to scrap its services was revealed on Monday, and was today described by Qantas as a "real kick in the guts" to Kangaroo Island residents amid an exchange of words between the rival airlines.

"Qantas is stepping up to support Kangaroo Island after a quite surprising decision this week by Regional Express [Rex] to exit the market between Adelaide and Kangaroo Island," QantasLink chief executive John Gissing said.

"We can only imagine how shocked the community on Kangaroo Island must have felt.

"We will move to increase our capacity and frequency from five flights a week to 12 — that's more than doubling our capacity.

"We will also be re-timing those flights which will get us much better connectivity to Australia's largest domestic network and the Qantas international network."

Rex has accused Qantas of pushing it out of the market by flooding the route with excess seats and has made a complaint to the Australian Competition and Consumer Commission (ACCC).

Regional Express has accused Qantas of forcing it out. ( Rex )

Deputy chairman John Sharp said he wanted to see the people of Kangaroo Island properly serviced, and said his company planned to continue operating flights until Qantas increases its capacity.

"We'll continue our air service operating until such time that Qantas can step in and take our place … so that the people of Kangaroo Island, its businesses, the people who live there and its tourists … are able to access a good, safe and reliable service," he said.

But he warned the South Australian Government would need to monitor prices closely once Qantas gained a monopoly on flights to and from the island.

"We recently introduced a community fare for Kangaroo Island of $99, and I note from the announcement from the CEO of QantasLink that they plan to put in some $99 fares," he said.

"So, we hope that they won't price gouge [but] it's very much up to the State Government to keep an eye on them."

Rex leaves door open on possible return

A campaign urging tourists to book out the island's accommodation is currently underway, following the bushfire crisis.

Mr Sharp said Rex "could possibly come back to KI in the future", but only if the route became more profitable.

"Rex would love to keep operating to Kangaroo Island … [but] we're not a big enough company to keep losing money on a particular route," he said.

"What we would say is that if the community of South Australia wants us to keep operating then yes, we're happy to work with the South Australian Government to find a way to keep doing that."

QantasLink chief executive Mr Gissing said any airline that wished to add services to the route could do so at any time.

"Like all unregulated routes, competition is open to any player that comes and make no mistake — we have competition", he said.

"There's competition from other destinations and there is always competition with the ferry."

Rex is expected to announce an exit date in the coming days.

Qantas began direct flights to Kangaroo Island in December 2017, two years after an upgrade to the local airport was revealed.