CARACAS, Venezuela — President Hugo Chávez of Venezuela experienced complications related to his cancer surgery, resulting in bleeding that required “corrective measures,” but he was showing signs of recovery, an official said Thursday.

The surgery, which lasted more than six hours, was done in Havana on Tuesday. Ernesto Villegas, Mr. Chávez’s information minister, did not say when doctors detected the bleeding or got it under control. But he said that Mr. Chávez was recuperating in a way that he described as “progressive and favorable.”

Given how little information the government has released on Mr. Chávez’s health throughout the course of his illness, the recent change in its tone suggests that his condition is extremely serious and that there are doubts about how fully he may recover.