HAVANA - Ailing Cuban leader Fidel Castro on Tuesday told hundreds of admirers who traveled here for his 80th birthday celebrations that he is not well enough to meet with them yet.

Tiny dancers of Guaracheritos de Regla get ready to perform during a cultural act at the San Geronimo College dedicated to Cuban leader Fidel Castro for his 80th birthday in Old Havana,Cuba, Tuesday, Nov. 28, 2006. Presidents, former leaders and Nobel laureates have confirmed their attendance at a five-day 80th birthday bash for ailing leader Fidel Castro. [AP]

"I'm not in medical condition to be there," Castro said in a statement read by a presenter to thousands of supporters from dozens of countries at the start of a gala in Havana's Karl Marx theater that was to mark the opening of the celebrations.

Fidel Castro's 80th birthday celebration kicked off on Tuesday without the ailing Cuban leader in sight but hundreds of admirers from around the world were on hand to pay homage.

The opening of an art exhibit by Castro's favorite artist, Oswaldo Guayasamin, was the first of five days of events.

A "Cuban gala" show was due to be followed on Wednesday with a colloquium on Castro's place in history, a concert and a military parade in Havana's main square on Saturday.

Castro has not been out in public since undergoing emergency surgery for an undisclosed illness that forced him to temporarily hand over power to his brother Raul on July 31.

Questions about whether he will be well enough to put in an appearance this week have dominated the run up to the event and overshadowed its celebratory intent.

Cuban Culture Minister Abel Prieto said at the art exhibit that he still does not know what Castro's plans are. "I do not know if he will show up. He is aware of the event and has been asking how it is going," Prieto told reporters.

After the release on October 28 of a video that showed a gaunt, shuffling Castro, many Cubans believe he is too old and too ill to resume governing.

"More than a birthday celebration, what we will see on December 2 will be a farewell," Ramon, a 55-year-old retired soldier, said in the eastern Cuban city of Santiago.

Castro's absence did not dampen the enthusiasm of visitors who came from as far away as Ethiopia and Laos for the celebration of a man they view as a champion of Third World countries.

"We came to celebrate his birthday. Twenty-five years ago he did a good job for the Ethiopian people," said artist Lemma Guya, recalling the thousands of Cuban troops Castro sent to fight in his country and hundreds of doctors who served there.

"Fidel Castro is a representative of oppressed peoples and activist intellectuals," said left-wing American author and State University of New York professor James Cockcroft. "All of us are worried about his health."

Officials said 1,500 guests from 80 countries will attend the celebrations, including presidents Evo Morales of Bolivia and Rene Preval of Haiti and president-elect Daniel Ortega of Nicaragua.

Venezuelan President Hugo Chavez, Castro's top ally and equally fierce critic of the United States, is not expected to make the event because he faces a national election on Sunday.

The celebrations were originally scheduled for Castro's actual birthday on August 13.

Due to his illness he asked that they be postponed until Dec 2, the 50th anniversary of the day he and a group of followers landed in Cuba to start a guerrilla movement that seized power in a 1959 revolution.