HAVANA — Social media around the world have been flooded with rumors of Fidel Castro's death, but there was no sign Friday that the reports were true, even if the 88-year-old former Cuban leader has not been seen in public for months.

Similar speculation has swept across Cuban expatriate communities repeatedly over the decades, particularly after a serious illness forced him to step down from duties as president in 2006, handing over leadership to his younger brother Raul.

The new wave was prompted in part by Fidel Castro's failure to comment after the U.S. and Cuba declared on Dec. 17 that they would move to restore full diplomatic relations broken a half century ago.

The chatter appeared to pick up when some media noted Thursday that Castro had not been seen in public in a year. He last appeared on Jan. 8, 2014, at an art exhibition in Havana, ending nine months out of public view.

The most recent official photographs of Castro came out of a private meeting with Venezuelan President Nicolas Maduro on Aug. 21. He was also photographed with the Chinese and Russian presidents in July. Castro was last heard from on Oct. 18, when he published an editorial about Ebola.

By Friday, Cuba-related Twitter accounts were ablaze with speculation, fueled in large part by reports on news websites such as Diario de Cuba and Diario las Americas that Cuba had scheduled a news conference, possibly to discuss Castro's health.

The rumors were further stoked when respected Italian newspaper Corriere Della Sera reported on its website that Castro had died. It quickly pulled the report back, however.

Cuban officials told news media in Havana that no press conference had been called, and there were no obvious signs of official preparations for mourning.