MIAMI (CNN) -- Ten people were charged Monday with attempting to
                  infiltrate U.S. military bases, disrupt anti-Castro groups and manipulate
                  U.S. media and political groups for the Cuban government, federal
                  investigators said.

                  Federal prosecutors said three suspects from the "unparalleled spy ring"
                  were members of the Cuban military who had attempted to infiltrate at least
                  three U.S. military facilities in Florida.

                  The prosecutors said the arrests dealt a "significant blow" to the Cuban
                  government.

                  The suspects were charged with a variety of espionage-related offenses,
                  including being an agent of a foreign government and conspiracy to
                  defraud the United States as unregistered agents of a foreign power.

                  The prosecutors said the suspects gave the Cuban government
                  information gathered from the U.S. Southern Command in Miami, the Boca
                  Chica Naval Air Station in Key West and McDill Air Force Base in Tampa.

                  An FBI affidavit filed when the eight men and two women made their court
                  appearance says that all 10 members operated with code names and had
                  escape plans and alibis in case they were arrested.

                  It was not immediately clear whether they were Cuban exiles, agents who
                  slipped into the United States from Cuba, or some of each.

                  Congressional sources said the arrests, which were made on Saturday, were
                  timed to avert an operation planned by the suspects, but they provided no
                  details.

                  1 suspect worked at Navy base

                  The prosecutors said that one suspect, employed at Boca Chica
                  Naval Air Station, reported on aircraft movements and gave
                  names and addresses of base personnel to the Cuban
                  government.

                  Prosecutors said that some of the others tried to gain employment at
                  the U.S. Southern Command, but were unsuccessful.

                  Among the accused is Rene Gonzalez, who was formerly affiliated with the
                  Miami-based Cuban exile group Brothers to the Rescue, which flies
                  search-and-rescue missions over the 90 miles (145 kilometers) of open
                  water between Florida and Cuba.

                  The group uses small U.S.-registered aircraft in its search for rafters fleeing
                  the communist island nation.

                  In February 1996, a Cuban MiG jet fighter shot down two Brothers to the
                  Rescue planes over international waters. Four men were killed, three of them
                  Americans.

                  According to Jose Cardenas, spokesman for the Cuban American National
                  Foundation (CANF) in Washington, the accused spies had infiltrated the
                  Brothers, among other Cuban exile groups.

                  Suspects arrested Saturday

                  Gonzalez has been linked more recently to Ramon Saul Sanchez's
                  Democracia movement, which sails flotillas from the Florida Keys to areas
                  near Havana to protest Cuban government actions.

                  Sanchez said he is not shocked that his group has been infiltrated by spies.

                  "We screen people," he said. "We do not pretend that we could not be
                  infiltrated. The FBI, CIA and KGB have also been infiltrated."

                  The suspects were arrested without incident Saturday by the FBI in the
                  Miami area.

                  Beside Gonzalez, the suspects are Ruben Campa, Luis Medina, Alejandro
                  Maximus Alonso, Linda Hernandez, Nilo Hernandez, Manuel Viramontez,
                  Joseph Santos, Antonio Guerrero and Amarilys Santos.

                  It was not immediately clear whether they were Cuban exiles, agents who
                  slipped into the United States from Cuba, or some of each.

                  Freeh calls congresswoman

                  FBI Director Louis Freeh called U.S. Rep. Ileana Ros-Lehtinen at her home
                  on Saturday to inform her of the arrests, said her spokesman, Juan Cortinas.

                  Ros-Lehtinen, a Cuban-born Miami Republican, wrote the FBI in June
                  asking the agency's counterintelligence section to brief her on two types of
                  activities by Cuban officials in the United States.

                  She said she was concerned about "a significant increase" in travel by Cuban
                  officials to Florida and New York for private meetings and an "inordinate
                  number of meetings that Cuban government officials have been holding with
                  major U.S. corporations and industry giants."

                            The Associated Press contributed to this report.