Castro, who has presided over the island's communist government for almost 48 years, temporarily handed over his duties to his brother Raul, the defence chief, on July 31. Neither Castro has appeared in public since.

Due to "concrete threats" from Washington, "the information that we give about this whole situation has to be careful, limited to inform what is indispensable," National Assembly speaker Ricardo Alarcon said in an interview with Radio Rebelde.

Sources close to Fidel Castro's circle, however, said that the surgery was believed to have been performed early July 27, and that a few days later Castro was ingesting light food, and that now he reads documents.

Alarcon justified limited disclosure, referring to the 10-year-old US Helms-Burton law that establishes the US goal "to put an end to the revolutionary government."