MADRID (Reuters) - At least two of the 12 Moroccan passengers hunted by police following an emergency landing on the Spanish island of Mallorca escaped by ferry to Barcelona, police sources said on Tuesday.

       An Air Arabia Maroc flight from Casablanca to Istanbul diverted to Palma de Mallorca airport on Friday after a passenger falsely claimed to be ill, police said.

       Twenty-four passengers fled the plane, closing the airport for more than three hours, in what media believe to have been an elaborate ploy to enter Spain illegally.

       Authorities arrested 12 people and were looking for 12 others.

       The passenger who triggered the emergency was released from hospital and arrested after staff determined he was not ill.

       Officials are investigating whether the whole incident was the result of a Facebook group's plan to enter Spain illegally, El Pais newspaper said.

       At least two of those who fled took a ferry from Mallorca to Barcelona and were still at large, police sources told Reuters.

       Spain's National Police did not immediately respond to requests for comment.

       A judge ruled on Monday that 12 defendants would remain in custody under preliminary charges of sedition and coercion. The judge did not elaborate.

       Two were also charged with aiding illegal immigration, the Balearic Island top court said in a statement.

       (Reporting by Graham Keeley; Editing by Nick Macfie)