CARACAS, Venezuela – Voters chose Sunday between the hand-picked successor who campaigned to carry on Hugo Chavez’s self-styled socialist revolution and an emboldened second-time challenger who warned that the late president’s regime has Venezuela on the road to ruin. Tensions rose soon after polls closed as both sides hinted at victory and suggested the other was plotting fraud.

Jorge Rodriguez, the head of the campaign for acting President Nicolas Maduro, said he couldn’t reveal the results before electoral authorities did but strongly suggested Maduro had won by smiling and summoning supporters to the presidential palace, where Chavez’s supporters gathered to celebrate the late president’s past victories. And he warned that Maduro’s camp would not allow the will of the people to be subverted.

Opposition challenger Henrique Capriles and his campaign aides immediately lashed out at Rodriguez’s comments.

Ramon Guillermo Aveledo, a Capriles campaign coordinator, suggested the government was trying to steal the election.

“They know perfectly well what happened and so do we,” he said at a hastily called news conference. “They are misleading their people and are trying to mislead the people of this country.”

Capriles also suggested fraud was in the works in a Twitter message: “We alert the country and the world of the intent to change the will of the people!”

In an earlier tweet, Capriles urged his supporters not to be “desperate and defeated.”

Bill Richardson, the former New Mexico governor and longtime U.S. ambassador-at-large who came to witness the election, told The Associated Press that both candidates had assured him they would respect the outcome of the vote.

“I’m not here as an election observer, but I met with both candidates — Maduro, yesterday, and Capriles today. And I’m hopeful because both told me they would respect the rule of law and the will of the people,” Richardson said.

Maduro, the 50-year-old longtime foreign minister to Chavez, pinned his hopes on the immense loyalty for his boss among millions of poor beneficiaries of government largesse and the powerful state apparatus that Chavez skillfully consolidated.

Maduro’s campaign was mostly a near-religious homage to the man he called “the redeemer of the Americas,” who succumbed to cancer March 5. He blamed Venezuela’s myriad woes on vague plots by alleged saboteurs that the government never identified.

Capriles’ main campaign weapon was to simply emphasize “the incompetence of the state,” as he put it to reporters Saturday night.

Maduro’s big lead in opinion polls was cut in half over the past two weeks in a country struggling with the legacy of Chavez’s management of the world’s largest oil reserves.

Millions of Venezuelans were lifted out of poverty under Chavez, but many also believe his government not only squandered, but plundered, much of the $1 trillion in oil revenues during his tenure.

Venezuelans are afflicted by chronic power outages, crumbling infrastructure, unfinished public works projects, double-digit inflation, food and medicine shortages, and rampant crime. Venezuela has one of the world’s highest homicide and kidnapping rates.

“We can’t continue to believe in messiahs,” said Jose Romero, a 48-year-old industrial engineer who voted for Capriles in the central city of Valencia.

Voting lines seemed considerably lighter than in the October election that Chavez won, when more than 80 percent of the electorate turned out, although government officials said it was due to the improved efficiency of the system.