Images appearing to show former Cuban President Fidel Castro surfaced Saturday on a pro-government blog, which claims the photos were taken Wednesday.
The photos apparently show the 83-year-old ailing Castro meeting with people during "a surprise visit" at the National Center of Scientific Investigations in Havana, according to a blog published by columnist Rosa C. Baez.
The Cuban government was not immediately available to comment on the authenticity of the photos, and CNN's attempts to reach the Havana-based blogger were unsuccessful.
It would be the first public appearance made by the former Cuban leader since he stepped down from power in 2006 to undergo intestinal surgery.
Raul Castro was formally elected president in 2008.