Fidel Castro denounced the pending release in the United States of a jailed Cuban militant who was once a U.S. operative, accusing the American government of planning to free a "monster." Family members of bombings blamed on Luis Posada Carriles joined a protest Wednesday, saying that freeing him would be risky.

Castro's charges came in a signed letter distributed by Foreign Ministry officials after U.S. District Judge Kathleen Cardone refused earlier Tuesday to reverse her decision allowing Posada to be released on bond.

"The answer is brutal," Castro wrote. "The government of the United States and its most representative institutions have decided the liberation of the monster beforehand."

The letter was the third in recent days signed by the ailing Cuban leader, who has not been seen in public for more than eight months. Castro, 80, announced July 31 he had undergone emergency intestinal surgery and provisionally ceded his presidential functions to his 75-year-old brother, Raul, the defense minister.

Fidel Castro's medical condition and actual ailment remain a state secret, but he is widely believed to suffer from diverticular disease, a common affliction among the elderly that causes inflammation and bleeding in the colon.

Cardone ruled in El Paso, Texas on Friday that Posada could be released on US$250,000 bond from the Otero County jail in New Mexico, pending trial on charges of lying to immigration authorities in a bid to become a naturalized citizen.

Posada's family members in Miami must still post a $100,000 personal surety bond, said Arturo V. Hernandez, Posada's lawyer in Miami. The family members — his wife, daughter and son — also have to sign custodianship affidavits committing to act as Posada's supervisor upon his release, Hernandez said.

Posada, a former CIA operative, is wanted in Cuba in the 1976 bombing of a Cuban jetliner that killed 73 people, a charge Posada denies. Castro repeatedly has accused the U.S. government of protecting Posada by holding the 79-year-old on a far less serious charge.

Castro also drew a connection between "the criminal and terrorist character of the accused" and the current U.S. government. "The most genuine representative of the system of terror that has been imposed upon the world by the technological, economic and political superiority of the most potent power in the world is, without question, George W. Bush," his statement said.

Relatives of people whose deaths were blamed on Posada gathered in Havana Wednesday to denounce his possible release.

"Every time I hear the name of Posada Carriles my personality changes completely," said Giustino di Celmo, whose 32-year-old son Fabio, an Italian tourist, was killed in one of a string of 1997 Havana hotel blasts allegedly masterminded by the Cuban-born militant.

"Before me, I see blood, blood and more blood," said the Italian-born Di Celmo, who moved to Havana after his son's death. "It is time to adopt a human policy in this case."

Di Celmo said releasing Posada on bond could be risky, adding that "a person like that, who is still protected by the United States government, could flee."

Posada is a longtime foe of Castro, who publicly accused him at a 2000 presidential summit in Panama of plotting to assassinate him. Posada was soon afterward arrested in Panama and convicted on lesser charges before walking free in 2004, after being pardoned by Panama's president at the time, Mireya Moscoso.

Cuba accuses Posada of being the mastermind of the 1976 Cubana airliner bombing off Barbados.

Venezuelan authorities want to extradite Posada for trial in that South American country, where he is a naturalized citizen. Posada was arrested in Venezuela a few days after the bombing and escaped from prison there in 1985 before a civilian trial in the case was completed.

Posada was detained in Florida in May 2005 for entering the United States illegally. A U.S. immigration judge ruled that he could not be sent to Cuba or Venezuela, citing fears that he would be tortured.

Posada trained with the CIA for the 1961 Bay of Pigs invasion and served in the U.S. Army in the early 1960s.