A military parade marking the 50th anniversary of the date Fidel Castro and his rebels landed in Cuba to launch their revolution started Saturday in Havana without the ailing leader, fuelling speculation that he may not return to power.

Many Cubans still hoped that Castro would make at least a brief appearance during the military parade, which culminates five days of celebrations for his 80th birthday. He has not been seen in public since July 26.

Cuba's acting president Raul Castro, left, brother of ailing Cuban leader Fidel Castro, chats with Colombian writer Gabriel Garcia Marquez.
(Javier Galeano/Associated Press)

Acting President Raul Castro, who is Fidel's younger brother and the island's defence minister, made no mention of the elder Castro's absence during a half-hour speech. The acting president instead focused on criticism of the U.S. government and praised the Cuban revolution, saying it marked "a transcendental act in our history."

Fidel Castro turned 80 on Aug. 13 but delayed the celebrations to give him time to recover from surgery two weeks earlier for intestinal bleeding. Few details about his condition have been released by Cuba's communist government.

Cuban officials insist Castro is recovering, but U.S. officials say they believe he suffers from some kind of inoperable cancer and will not live through the end of 2007. He has appeared thin and pale in photographs and videos released by the government since he temporarily ceded power to his brother.

Cuba's Revolutionary Armed Forces, which replaced the military that existed before the Cuban Revolution, traces its roots to Dec. 2, 1956, when 82 rebels landed on the island on a yacht — the Granma — that sailed from Mexico.

The Castro brothers were among fewer than two dozen rebels who survived the landing to reach the mountains, where they launched a guerrilla war against then-president Fulgencio Batista. Their revolution triumphed on Jan. 1, 1959.

Fidel Castro purportedly sent a message to those celebrating his birthday earlier this week, telling a crowd of 5,000 supporters at the opening event Tuesday at a Havana theatre that he was too sick to meet with them.

"I direct myself to you, intellectuals and prestigious personalities of the world, with a dilemma," said a note read at the event. "I could not meet with you in a small locale, only in the Karl Marx Theater where all the visitors would fit, and I was not yet in condition, according to the doctors, to face such a colossal encounter."

More than 1,300 politicians, artists and intellectuals from around the globe were attending the tribute to the man who has governed Cuba for 47 years, including Bolivian President Evo Morales, Haitian President Rene Preval and Colombian Nobel laureate Gabriel Garcia Marquez.