Carnival Corp. is being sued in Miami federal court over its adherence to Cuba's policy that prevents Cuban nationals from arriving or departing the island by sea.

Two Cuban-Americans are claiming their civil rights were violated because they were not permitted to buy tickets on a May 1 cruise from Miami to Cuba aboard Carnival's Fathom cruise line.

The potential class-action lawsuit filed Tuesday asks a judge to force Carnival to allow all people of Cuban origin to sail on cruises to Cuba. The lawsuit was filed the same day Cuban Americans staged demonstrations against the policy outside Carnival headquarters in Doral.

The company says in a statement it must comply with the visa, entry and exit policies of every country, but has lodged a request with the Cuban government to change the ship policy.