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Memorials will be held in Miami today over the 15th anniversary of the Brothers to the Rescue tragedy -- when the Cuban military's shot down exile planes dropping pro-democracy leaflets over Cuba.

Four members of the organization were killed.

Outrage among Cuban exiles over the 1996 shooting halted the Clinton administration's tentative efforts to reach out to the communist government and paved the way for the Helms Burton Act, which turned the U.S. embargo to Cuba into permanent law. Previously it had been maintained under an executive order that a president could rescind at any time.

Relatives and supporters planned to join survivors and other members of the Brothers to the Rescue group at the Opa-locka Airport from where the planes took off in 1996 and later at a memorial in Hialeah Thursday afternoon. The group had been warned about flying over Cuban airspace but says its pilots were not over Cuban airspace when they were attacked.

During the 1990s, the group also helped identify and rescue Cubans fleeing the island by boat through the treacherous Florida Straits.

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The Hermanos al Recate anniversary comes one day after the first anniversary of the death of Cuban political prisoner Orlando Zapata Tamayo following an 83-day hunger strike. He was imprisoned for disrespecting authority.

Zapata's death drew worldwide attention to the plight of the island's dissidents in advance of that anniversary, the Cuban government detained Zapata's mother for 12 hours.

On Wednesday, the U.S. issued a statement condemning the treatment of Zapata's mother and commemorating his death. The statement did not include any reference to the Brother to the Rescue anniversary.

Based on reporting by The Associated Press.

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