BY ROMINA GARBER

Already angered by impending rule changes limiting travel to Cuba, scores of people felt doubly mistreated Tuesday when they were turned away from their scheduled flights at Miami International Airport.

With stricter regulations on travel to Cuba taking effect today, many had been looking to beat the deadline by flying there a day earlier. But it turned out that the charter airlines that sold them their tickets had not been authorized to do so by the State Department -- and that neither were the flights authorized to take off.

The hopeful travelers -- paid up and packed -- were reduced instead to lining up at MIA and chanting, ''We want to fly,'' The Associated Press reported.

State Department spokesman Tom Casey said it had granted Americans currently visiting Cuba an extension until July 31 to return since the original June 30 deadline could have made it difficult for everyone to get back in time.

''What we understand,'' he said, ``is that, prior to the extension of the deadline, a couple of charter operators had basically put together flights that would have gone down to Cuba empty and picked people up, then returned to the States full, yet when the extension was granted, these charter operators turned around and requested licenses to take additional people to Cuba in the last couple of days in June.''

Approving such requests, Casey said, would have been inconsistent with State Department policy designed to reduce the amount of foreign currency going into Cuba and would have made it more difficult to get back from the island in an orderly fashion.

''We recommended that those licenses to bring people down to Cuba not be approved,'' Casey said. ``Obviously, applying for a license doesn't mean you're going to get it.''

NOT ALL ARE ON BOARD

Critics say the new policy will only hurt people in need. Jorge Luis Rodríguez was among the passengers stranded at the airport.

''The whole world can travel to their countries whenever they want, but we can't,'' he told The Associated Press, adding that he was trying to visit his sick mother, 81, who lives outside Havana.

For supporters of the new rules, the concerns of businesses and some members of the exile community are outweighed by the well-being of the majority.

''What we're talking about is freedom for 12 million Cubans, not for an elite who can afford to travel there,'' said Ninoska Pérez Castellón of the Cuban Liberty Council, an exile group in Miami.

Eleven of the 16 flights scheduled to leave MIA for Cuba on Tuesday did so without passengers. They had State Department approval nut only to bring people back to the States, airport spokeswoman Insom Kim told The Associated Press.

Gulfstream Air Charter was among those, according to airport spokeswoman Trenae Floyd. It had sold flights to Cuba but canceled them Tuesday by informing passengers, through a statement, that the State Department had not cleared its plane to transport passengers from Miami to Cuba.

NO ROUND TRIPS

''Gulfstream previously arranged for an air carrier to operate one-way flights from Havana to Miami today and had hoped it could convert the flights to round-trip charters operating Miami-Havana-Miami,'' the statement read.

Gulfstream representatives declined further comment. The charter's passengers must contact their travel agents to get refunds.