Castro has not been seen in public since surgery in July

Ailing Cuban leader Fidel Castro is in a serious condition following three failed operations, according to Spain's El Pais newspaper.

Mr Castro is suffering from a serious intestinal infection, the report says.

It cites medical sources at a Madrid hospital whose top surgeon travelled to Cuba in December to examine Mr Castro.

There has been no public indication of any deterioration in the president's condition, the BBC's Havana correspondent reports.

There has been considerable speculation about the health of Cuba's 80-year-old leader since he underwent urgent intestinal surgery in July.

He has not been seen in public since then, and in December missed a massive military parade in Havana marking 50 years since his return from exile.

In his New Year message, he said he was recovering slowly from the surgery, but said it would be a "long process".