The cruise ship ran aground above the Arctic Circle on Monday in Alpefjord, which is in the Northeast Greenland National Park, the world’s northernmost national park.

The operator of a luxury cruise ship that ran aground in Greenland with 206 people on board said Thursday at least three passengers have contracted Covid-19. The announcement followed a third failed attempt to free the cruise liner, after a fisheries research vessel attempted to pull the ship free at high tide on Wednesday.

“These passengers are currently in isolation. They are looked after by our onboard doctor, medical team and crew, and they are doing well,” the Australia-based Aurora Expeditions said in a statement. The others on the MV Ocean Explorer were “safe and healthy,” it added.

Australian newspaper The Sydney Morning Herald quoted a retiree from Australia, Steven Fraser, who is on the ship, saying: “Everyone’s in good spirits. It’s a little bit frustrating, but we are in a beautiful part of the world.”

Fraser told the newspaper that he himself had come down with Covid-19 on the ship.