Former President Fidel Castro says the attitude and comments of a popular Cuban blogger only add fuel to attacks against the communist country by its enemies.

Without mentioning her by name, the ailing 81-year-old criticized Yoani Sanchez, who posts the "Generation Y" blog from Havana, in the prologue of a new book about his relationship with Bolivia. The book, "Fidel, Bolivia and Something More," went on sale in Cuba this week.

The 32-year-old Sanchez has gained wide international attention recently, especially after Cuba last month denied her permission to travel to Spain to receive the prestigious Ortega y Gasset journalism award for her blog.

Castro made reference to the fact that Sanchez spoke to an international news agency about not being able to travel to Spain for the award ceremony.

"What is grave isn't so much affirmations of this type that are divulged immediately by imperialism's mass media," Castro wrote, but that there are young Cubans who "assume the job of those who undermine, and of the neocolonial press of the ancient Spanish metropolis that awards them."

Although her widely read blog has criticized the communist government, Sanchez has never been arrested.

Castro resigned the presidency for health reasons in February and was succeeded by his younger brother, Raul.