Venezuela's President Hugo Chavez celebrated his 58th birthday Saturday by stepping up his re-election campaign.

Though doubts remain about the leftwing leader's health following a bout with an undisclosed form of cancer, Chávez appeared vigorous at Saturday's campaign event. He declared himself cancer-free earlier this month. 

Chavez rode atop a truck and waved to crowds of supporters in the Caracas slum of Petare. He hugged and kissed two of his daughters on a stage where he sang and danced alongside a band. His supporters sang "Happy Birthday."

"I want to thank everybody for the messages I've been getting. ... Well, I made it to 58," Chavez told reporters, adding that Cuban President Raul Castro had called him and that he had also heard from his allies in Bolivia and Nicaragua.

Chavez said earlier this month that he is free of the cancer that forced him into months of treatments and caused speculation about whether he would be able to campaign.

Opposition candidate Henrique Capriles spoke at an event east of Caracas in Guarenas, where he swore in supporters who will monitor polling stations during the Oct. 7 vote. He said Chavez's government has wasted money while schools and roads remain in bad shape. Capriles noted that one Caracas hospital has been in construction for years and called it a "monument to corruption."

Capriles also pointed to blackouts, double-digit inflation and seizures of private companies that he said have cost jobs. "He doesn't have anything new to offer," Capriles said of the president, who has been in office since 1999 and is seeking another six-year term.

Over the past 13 months, Chavez has undergone two surgeries that removed tumors from his pelvic region, most recently in February.

The socialist leader has not disclosed key details about his illness, including the type of cancer that had been diagnosed.

Chavez has stepped up his public appearances in recent weeks, but he has led fewer rallies than Capriles, who has been campaigning energetically, sometimes jogging, in cities and towns across the country.

During the first 15 days of the campaign, which formally began on July 1, Capriles boasted of visiting 53 towns. Chavez, in contrast, made a handful of campaign visits during that period.

Chavez has seemed to favor his right hip at times, but he showed off his mobility earlier this month when he climbed into the cockpit of a Russian-made Sukhoi fighter jet during one military event.

"Chavez has appeared more, but it's a far cry from the Chavez of 2006," the last presidential vote, said Jose Vicente Carrasquero, a political science professor at Venezuela's Simon Bolivar University. He said Chavez's advisers "have realized that the need to appear is fundamental" in facing his younger challenger.

Chavez has been leading in most recent polls, though his lead over Capriles has varied widely depending on the survey. A large segment of voters, more than 20 percent in some surveys, has not revealed a preference for either candidate.

As Chavez spoke to the crowd in Petare, they waved flags and blew horns. He told his supporters: "We need to work very hard."

"Our lead, I'm not going to say it's comfortable, no. But it's a good lead. Now we have to hold on to it and widen it," Chavez said.

Based on reporting by the Associated Press.

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