Low-key 81st birthday for absent Fidel Castro

HAVANA, Aug 13 (Reuters) Children today sang ''Happy Birthday, Fidel'' in Havana's Lenin Park to mark the birthday of Cuba's ailing and absent 81-year-old leader Fidel Castro.

But there was no official birthday bash for Castro, who has not appeared in public since emergency bowel surgery forced him to hand over power to his brother Raul more than a year ago.

A fireworks display at midnight closed a week of Carnival festivities along Havana's Malecon sea-front boulevard and was not dedicated to Castro's birthday.

Cuba's state media ran eulogies of Castro, the last major Cold War figure still alive, saying the Cuban people still backed the socialist system born of his 1959 revolution.

The Communist Party newspaper Granma published on its front page greetings from five Cuban agents imprisoned in the United States, where they were sent to spy on anti-Castro groups.

''Happy Birthday, from a prison of the Empire where you are in my heart every day,'' wrote Antonio Guerrero, who is serving a life-sentence at Florence Penitentiary, in Colorado, for spying on a Florida military airfield where he worked as a janitor.

The low-key celebrations contrasted with Castro's last birthday, when his main ally, Venezuela's populist President Hugo Chavez, visited him in a hospital. Pictures of the meeting helped convince the world that Castro had survived a life-threatening illness.

Uncertainty still surrounds Castro's health and his illness is a closely-guarded state secret that has not leaked from his inner circle in a year.

Cuba's Communist authorities maintain Castro is recovering from his health crisis, but they are no longer saying he will return to office. By all accounts, his brother Raul Castro is running the country.

While Castro has been out of sight for a year, he has not been out of mind, thanks to regular newspaper columns with his musings on problems he says threaten human survival, mostly blamed on his capitalist archenemy, the US government.

''Our main wish is that you will continue to be with us,'' leftist President Evo Morales said in a greeting from Bolivia.

''You are symbol ... of the Latin American revolution. Your struggle has not been in vain.'' On the gritty streets of Havana, few expect to see Castro ever again in his trademark olive green fatigues delivering a thundering hours-long speech in Revolution Square.

''The Comandante will not show up. His health no longer permits that. I think he is not coming back,'' said retired state employee Jose Manuel, 73, sitting on a park bench as his grand-children played.

Like many other Cubans, Manuel believes the uncharismatic Raul Castro is doing a good job in his brother's shoes, preparing changes that will open up the state-run economy while preserving Cuba's social gains in education and health.

In Lenin Park on the outskirts of Havana, several hundred children wished Castro a rapid recovery as they celebrated his birthday around a giant birthday cake in a well-scripted event at a pavilion named after guerrilla icon Ernesto Che Guevara.

''Get better, Comandante, and continue helping us,'' said 6-year-old Zeida Amor. Edisley Oquendo, 12, said: ''He must look after himself to get better and continue leading this nation.'' Reuters SBA VP0115