Three of 78 Indonesian crew members on board the Diamond Princess cruise ship anchored off Yokohama in Japan have tested positive for the coronavirus, Indonesian Foreign Minister Retno Marsudi said yesterday, as more nations moved to evacuate their citizens from the stricken vessel.

Two of them were being treated for Covid-19 at a hospital in the city of Chiba, while the third was being taken to a hospital.

Ms Retno said a team from the Indonesian Embassy in Japan is now in Chiba to ensure proper treatment for the two Indonesian nationals. Their families have been contacted.

"In the meantime, the embassy continues to communicate with other crew members who are still on board," Ms Retno told reporters, noting that plans were being made to evacuate them.

In its communication with Japan's Ambassador to Indonesia yesterday, Jakarta also demanded that the Japanese authorities ensure the cruise company can guarantee its crew members' rights, she said.

The three Indonesian nationals are among more than 540 people found infected on the ship, which has the biggest cluster of Covid-19 cases outside China, the centre of the outbreak.

Malaysian health director-general Noor Hisham Abdullah said two Malaysians on board the vessel had also tested positive for the virus and were being looked after by the Japanese authorities.

Meanwhile, Japan said all passengers and crew on the cruise liner have now been tested for the coronavirus. Starting tomorrow, it plans to let all those who tested negative after a two-week quarantine to disembark. It expects to complete disembarkation by Friday.

"We have done tests for everyone (on the ship)," Health Minister Katsunobu Kato was quoted by Agence France-Presse as saying.

"For those whose test results are already clear, we are working to prepare disembarkation."

But those who had close contact with the infected will have their quarantine reset to the date of their last contact, AFP reported. Crew will also observe another quarantine after the last passengers leave.

More countries are moving to evacuate their citizens from the ship, which was carrying as many as 3,711 people from 56 countries when it was quarantined.

South Korea yesterday sent a presidential aircraft to fly back four nationals and a Japanese spouse, The Korea Herald reported.

Britain, Canada and Taiwan also said separately yesterday that their governments would arrange for flights to evacuate their citizens from the stricken vessel, according to Reuters and AFP reports.

More than 300 Americans had already been evacuated from the ship on Monday, among them over a dozen who had tested positive for the virus.

The coronavirus has so far infected more than 73,000 people across the globe, and the death toll has hit more than 1,870.