Ruling party candidate Nicolas Maduro has narrowly won Venezuela's presidential election with 50.8 percent of votes, the electoral authority has said, allowing him to carry forward the policies of the late Hugo Chavez.
Maduro's challenger, Miranda state Governor Henrique Capriles, took 49.1 percent of the ballots, the authority said on Sunday, in a tighter-than-expected vote.
After a brief and bitter campaign, Venezuelans were forced to wait anxiously for results into Sunday night with counting reportedly too close to call and both sides expressing confidence of victory .
Al Jazeera's Lucia Newman, reporting from Caracas, said the situation was "extremely tense" and described the hard-fought election as a "nail-biter".
Capriles said there were attempts to let people vote after polling stations closed, and on Monday demanded a recount of the votes.
"This result does not reflect the reality of what Venezuelans want and aspire to," he said in Caracas. "Mr Maduro, if you were illegitimate before, now you are more so.
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of the presidential election
"I tell you firmly, this struggle is not over. It will end when Venezuela is a prosperous country when people can live better."
Our correspondent said it was unclear when a recount might start, and how long it would last.
"We demand a detailed recount in front of the world and the country," he said.
Earlier, Capriles accused the government of pressuring civil servants to vote for Maduro.
Maduro inherited Chavez's formidable electoral machinery, which helped the late leader win successive elections in 14 years, with government employees often seen handing campaign pamphlets and attending rallies in groups.
Both candidates had pledged during the campaign to recognise the vote results.
Capriles hopes discontent over the nation's soaring murder rate, chronic food shortages, high inflation and regular power outages would give him an upset victory.
What we want is for this country to have a true democracy
Capriles voted in an upper-class neighbourhood, kissing a statue of the Virgin Mary after voting and urging Venezuelans to report any election abuses.
"What we want is for this country to have a true democracy, a democracy for all, a country where we can all exercise our rights without the possibility of any reprisal," the 40-year-old state governor said.
Maduro was widely expected to win the right to complete the new six-year term Chavez won in October, promising to continue oil-funded policies that cut poverty from 50 to 29 percent with popular health, education and food programs.
Chavez named Maduro, a former bus driver and union activist who rose to foreign minister and vice president, as his political heir in December before undergoing a final round of cancer surgery.
Chavez died on March 5 aged 58.