Nicolás Maduro’s claim of victory in Venezuela’s presidential election has brought the South American country to a hazardous standoff, with his thwarted opponents accusing him of rigging the election to remain in power, and many leaders in the region and beyond questioning the veracity and transparency of the vote.

Late on Monday, street protests were reported across the capital and all around the country, including in the states of Falcón, where demonstrators were filmed tearing down a statue of Hugo Chávez, and Portuguesa, where footage showed a group vandalizing a propaganda billboard featuring a photograph of Maduro and a slogan promising “More Changes and Transformation”.

Riot police clashed with protestors and fired teargas at various locations.

The results, which followed an election described by independent observers as the most arbitrary in recent years – even by the standards of the authoritarian regime founded by Maduro’s mentor and predecessor, Hugo Chávez – appeared to have dashed opposition hopes of ending a quarter of a century of chavista rule and economic turmoil.

After a six-hour delay in releasing the results prompted international concern, the government-controlled electoral authority claimed Maduro had won with 51.21% of votes compared with 44.2% for his rival, the former diplomat Edmundo González Urrutia.

The council said that with about 80% of votes counted, Maduro had secured more than 5m compared with González’s 4.4m. Authorities delayed releasing the results from each of Venezuela’s 30,000 polling stations, saying only that they would be released in the “coming hours”.

On Monday morning, the electoral authority officially confirmed Maduro as the victor. “I assume the mandate of the people to be their president and lead our country towards peace and prosperity,” Maduro told an audience of allies, calling the result “irreversible”.

Critics blame Maduro, 61, for leading Venezuela into a crippling economic and social crisis, and turning the country into an increasingly repressive state where political opponents are routinely jailed and tortured.

Addressing supporters in the capital, Caracas, Maduro dedicated his victory to Chávez, who anointed him as his successor shortly before his death in 2013. “Long live Chávez. Chávez is alive!” Maduro shouted.

He added: “I am Nicolás Maduro Moros – the re-elected president of the Bolivarian Republic of Venezuela … and I will defend our democracy, our law and our people.”

But the opposition camp was quick to dispute the results.

“The Venezuelans and the entire world know what happened,” González said in his first remarks.

The opposition leader, María Corina Machado – who had thrown her weight behind González’s campaign after being banned from running – rejected the result, claiming the opposition had won in every single state.

“We won, and everybody knows it,” she said. “We haven’t just defeated them politically and morally, today we defeated them with votes,” Machado told journalists, claiming González should be considered the country’s president-elect.

Edison Research, which conducts high-profile election polling in the US and other countries, published an exit poll showing González had won 65% of the vote, while Maduro won 31%.

“The official results are silly,” said Edison’s executive vice-president, Rob Farbman, adding it stood by the results of its survey. Edison’s exit poll was conducted nationwide with preliminary data from 6,846 voters interviewed at 100 polling locations. Local firm Meganalisis predicted a 65% vote for Gonzalez and just under 14% for Maduro.

The Carter Center, which sent a team of electoral observers for the vote, called on the electoral authority to immediately publish the complete results by polling station.

Although Maduro’s allies in countries such as Cuba, Bolivia and Honduras congratulated him on his victory, key players including the US, Spain and the EU expressed deep reservations about the election and its results.

Later on Monday, Venezuela announced the expulsion of all diplomats from Argentina, Chile, Costa Rica, Peru, Panama, the Dominican Republic and Uruguay, and said it would withdraw its own representatives from those countries.

The US secretary of state, Antony Blinken, said Washington had “serious concerns that the result announced does not reflect the will or the votes of the Venezuelan people”.

He said the international community was watching the vote “very closely” and would react accordingly.

“It’s critical that every vote be counted fairly and transparently, that election officials immediately share information with the opposition and independent observers without delay, and that the electoral authorities publish the detailed tabulation of votes,” said Blinken.

Spain’s foreign minister, José Manuel Albares, also called on the electoral authority to release voting information in the interests of “respecting the democratic will” of the Venezuelan people.

“The people of Venezuela yesterday voted democratically and in very large numbers,” Albares told Spain’s Cadena Ser radio on Monday morning. “We want total transparency, and that’s why we’re asking for the results to be published, polling station by polling station. We don’t have a candidate – we just want a guarantee of transparency. The publication of polling station information is key so that the results can be verified.”

Josep Borrell, the EU’s most senior diplomat, said the will of the Venezuelan people had to be respected, adding: “Ensuring full transparency in the electoral process, including detailed counting of votes and access to voting records at polling stations, is vital.”

Many Latin American leaders, including Chile’s leftist president, Gabriel Boric, were far blunter in their assessment of Sunday’s vote.

“Maduro’s regime must understand that the results are hard to believe,” Boric wrote on X. “The international community and, above all, the Venezuelan people – including the millions of Venezuelans in exile – demand total transparency.” Chile, he added, “will not recognise any result that is not verifiable”.

Panama’s president José Raúl Mulino said his country was putting relations with Venezuela “on hold” and would withdraw diplomatic staff from Caracas until a full review of the result is conducted.

Others were more cautious. Mexico’s leftwing president Andrés Manuel López Obrador said he would only recognize a winner only after results were reported fully.
“We’re going to wait until they finishing counting the votes,” López Obrador told reporters.

Brazil – whose president, Luiz Inácio Lula da Silva, said recently he had been “frightened” by Maduro’s warnings of a “bloodbath” if he lost the vote – hailed a “peaceful” election day in Venezuela but said it was keeping a close eye on the vote count.

Celso Amorim, a former foreign minister who is now Lula’s chief diplomatic adviser, said the Brazilian government would only comment on the results after reviewing the records.

Amorim, who observed Sunday’s vote, said that while he was still familiarising himself with what happened, “the main issue is transparency”.

“The [Brazilian] government continues to monitor the situation until we have the necessary data to make an informed decision [on whether or not to recognise the results], as with any election,” he said in an interview with the Brazilian newspaper O Globo.

“It must be transparent. I’m not necessarily questioning what is being said, but the government was supposed to provide the records from which this number is derived, and that has not yet happened.”

González’s campaign had generated a rare wave of optimism among millions of disillusioned citizens after a decade during which the economy of the country with the world’s largest oil reserves contracted by 80% and nearly 8 million people – almost a third of Venezuela’s population – fled abroad.