The two women from the United States and Italy have been quarantined aboard the vessel Navigator of the Seas, owned by Royal Caribbean, along with their travel companions, but no one else on the ship has come down with the illness, a ministry official said. He did not know the total number of passengers on board.

The women will remain on the ship and it will leave as scheduled Wednesday night for Palma, on the Mediterranean island of Mallorca, the official said. There doctors will examine them again.

They will stay on the ship in quarantine because it is riskier to take them off and expose them to other people, the official said.

The ministry said Spain has now confirmed a total of 541 cases of swine flu in the country.