A police forensic team is on its way to the scene, with the deaths initially thought linked to a burnt-out car found near Parndana.

There have been no other reports of people missing or other injuries but three fire crews endured burn-overs in their trucks.

A watch and act warning remains in place for the fire which has now destroyed about 100,000 hectares including large parts of the Flinders Chase National Park.

South Australian Premier Steven Marshall said the deaths were tragic news.

"Our hearts go out to the families of those people who have been affected," he said.

"It really does reiterate the very important message that people listen to the alerts. This a very dangerous situation on Kangaroo Island."

Australian Community Media reporter Stan Gorton has been based in Kingscote on Kangaroo Island, and says there were audible gasps from the community as news was delivered that two people had died.

"We got some tragic news that we lost two people in the fire," he said.

"There's been extensive property losses. The community is in shock, just trying to digest the news - there's so much infrastructure and stock lost. It's going to take a while to recover from this and the Island will really need everyone's support."

He said the weather had now calmed down, with rain falling on the fire ground.

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Significant property losses are expected from the fire with major damage to tourism and other infrastructure also likely.

About 500 firefighters will continue to battle the blaze over the weekend, with crews and other resources brought in from the SA mainland.

The fire had been burning since late in December but escalated dramatically on Friday when it jumped containment lines during hot and windy conditions.

At one stage the entire island was subject to either an emergency warning or a watch and act advice with only the towns of Kingscote and Penneshaw on the east coast considered safe places.

By Saturday morning the situation had eased with cooler conditions providing an opportunity for fire crews to work on establishing fresh defences.

However, CFS chief officer Mark Jones said it was expected the fire would continue to burn for several days.

Mr Marshall said the government had already appointed a community recovery officer and would look at what additional support islanders would need in the coming days.

"It's clear that South Australia has had an extraordinarily difficult time with extensive damage right across our state," he said.

"Our focus at the moment is doing everything that we possibly can to contain the fire on Kangaroo Island.

"But very quickly our focus will move onto recovery."

Mr Marshall said he had also spoken to Prime Minister Scott Morrison on Saturday with the PM offering "all the support that is required".

At one stage on Friday, the blaze had threatened the towns of Parndana and Vivonne Bay, which were both evacuated, but both were spared any major damage.

The luxury Southern Ocean Lodge on the island's west coast was not so lucky, suffering structural damage, though the owners said all guests were moved to Kingscote or Adelaide before the threat intensified.

Six staff stayed to monitor the situation and activate the facility's emergency plan but all had since been accounted for and were uninjured.

The operators of the Sealink ferry service said up to 300 people were currently at a relief centre in Kingscote seeking passage to the mainland and it was working with authorities to get them on board as soon as possible.

The operators of the Kangaroo Island Connect ferry had also offered their services to move people off the island.

AAP