Former Cuban leader Fidel Castro, who has been out of the public eye for more than two months, is working on a book with Venezuelan President Hugo Chavez and is not at death's door, a pro-government blogger said on Wednesday.

Yohandry Fontana, who often is first to report official information and viewpoints, attacked a Barcelona-based blog and other social media for spreading the idea that Castro, who turned 86 on August 13, is seriously ill, and said there was "bad news" for them and "the creative boys of the CIA."

"Fidel Castro works together with Hugo Chavez on a book that will appear soon," Fontana wrote.

"The source that confirmed this information also said the Leader of the Revolution keeps up to date on the position of Ecuador regarding the case of (Wikileaks founder) Julian Assange, among other national and international issues that interest him," the blogger said.

Castro was last heard from publicly on June 19 when he wrote the last of a series of brief columns, or "reflections," published in Cuban state press.

His last known public appearance occurred on March 28 when he went to the Vatican embassy in Havana to meet Pope Benedict during his brief visit to the communist island.

Observers said he was stooped and needed assistance walking.

The man who took power in the 1959 Cuban revolution and ruled the country for 49 years has been in declining health since undergoing emergency surgery in July 2006 for an undisclosed intestinal ailment.

Citing his health and age, he resigned the presidency in February 2008 and was succeeded by brother Raul Castro.

He has occasionally fallen out of view for extended periods since then, always provoking speculation about his health, but reappeared each time saying he was working on a book or conducting research.

Chavez, a close Castro ally and Cuba's top benefactor, remarked on his friend's mental fitness via Twitter on August 13, after calling him to wish him happy birthday.

"It is impressive his energy and lucidity. He is an example of will and of revolutionary perseverance for all. Long live Fidel!!" he tweeted.

Chavez made no mention of the book said to be in the works.

Assange, who is facing extradition to Sweden for questioning about rape and sexual assault allegations, took refuge in Ecuador's embassy in London and has been granted asylum by that country's leftist government.

The British government issued a veiled threat to enter the embassy to seize Assange, which provoked an angry response from Ecuadorean President Rafael Correa.

Correa fears that Assange will be extradited from Sweden to the United States to face charges for publishing confidential U.S. government cables on Wikileaks.