Venezuela - Venezuela's Hugo Chavez will undergo another operation in Cuba in the coming days after doctors found a possibly malignant lesion in his pelvis where surgeons removed a large cancerous tumor last year, he said on Tuesday.

The 57-year-old socialist president confirmed he traveled to Havana for the tests on Saturday. Rumors of the unannounced trip had prompted a flood of speculation among the opposition and supporters alike that he was at death's door.

Chavez's health is the wildcard ahead of an October 7 presidential election, when he will seek a new six-year term. He has never given many details about his condition so the news he needs more surgery was bound to fuel doubts about his recovery.

"There is no metastasis, just this small lesion in the same place where they removed the tumor," the president said duringa televised tour of a factory in his home state of Barinas.

"Because of the growing rumors, I'm obliged to give this information now ... it's a small lesion, about 2 cm across, very clearly visible. This will need to be taken out, it needs more surgery, supposedly less complicated than before."

During one of two lengthy phone calls to state TV later in the evening, Chavez said the operation would take place in Cuba.

"I'll go to Havana. Everything is ready there, with the same doctors who operated on me before," he said. "To do it here we would have had to implement things, elements. It is safer there for this type of operation."

But he denied he was rushing back to Cuba: "All in due time. Tomorrow I'll be working all day, preparing myself for the weekend ... Unfortunately, I will not be able to continue at the same rate in the coming weeks."

Chavez said no one should be alarmed by the news, and that he was in good physical shape for the challenge ahead. Donning a bright red hard hat to stroll around the factory, the president had joked with workers and looked to be in reasonable health.

"No one can say if it (the lesion) is malignant, but there is a high probability because it is in the same place," he said.

He had insisted he was completely recovered, although medical experts had said it was too soon to make such a call.

One cancer doctor in the United States told Reuters that with such little detail it was impossible to know his real condition, but that the latest turn of events did not look good.