Security officials this month put the figure at more than 640.

But with protection and precaution, Castro had managed to stay on his feet, they say.

It has always been part of Castro's political strategy to underscore that Cuba -- and he -- were always at threat from the United States.

"The United States thinks that by killing leaders ... it can kill revolutions," he told a crowd of thousands in Holguin.

Cuba's fate, he has said, "does not depend on men, does not depend on individuals however selfless they may be, nor how committed to a cause; it depends on the conscience of each one of the country's citizens."

In June, a Cuban exile acquitted of plotting to assassinate Castro admitted in an interview that he had indeed planned to kill the Cuban leader in 1997.

Jose Antonio Llama, the former head of the Cuban-American National Foundation (FNCA), told Miami's El Nuevo Herald newspaper that he had been frustrated with the Castro regime's resilience following the collapse of the Soviet Union.

"We wanted to accelerate the democratization of Cuba using any means to get it," he was quoted as saying.

"That is the truth," he said. "The only thing I have at this point in life is the truth."

Llama said he decided to confess because FNCA has failed to return more than a million dollars he loaned the organization for the purchase of military equipment to be used against Castro and his government.

FNCA rejected Llama's allegations and claimed it was part of a "defamation campaign orchestrated by the Castro regime" in a bid to infiltrate and divide the Cuban exile community in the United States. The group said it was "committed to a peaceful and non-violent democratic transition in Cuba."

Llama and four other Cuban exiles were arrested in Puerto Rico in 1997 while on a boat carrying weapons allegedly to be used to shoot down a plane carrying Castro to an Ibero-American summit on Venezuela's Margarita Island. They were all acquitted.