The Organization of American States's (OAS) election observation department has said it cannot recognise the results by Venezuela's national electoral council declaring President Nicolas Maduro the winner of Sunday's disputed vote.
The 35-member regional body, which is to meet about Venezuela tomorrow, said Venezuela's National Election Council (CNE) had shown itself biased towards the government.
The CNE said Mr Maduro had won with 51% of votes, but the opposition said the 73% of vote tallies to which it has access showed its candidate Edmundo Gonzalez had more than twice as many votes as Mr Maduro.
Protests have erupted in Venezuela, while the United States and various Latin American leaders have rejected the results or said greater transparency is needed.
"The events of election night confirm a coordinated strategy, unfolding over recent months, to undermine the integrity of the electoral process," the OAS body's report said.
It contained accounts of illegalities and malpractices that occurred in this and past Venezuelan elections.
"The evidence shows an effort by the regime to ignore the will of the majority expressed in the polls by millions of Venezuelan men and women," the report said.
"What happened shows, once again, that the CNE, its authorities and the Venezuelan electoral system are at the service of the executive power, not citizens."
Mr Maduro says Venezuela has the best and most transparent vote system in the world, and accuses violent right-wing factions of seeking to overthrow him illegally with foreign support.
He has received backing from China, Russia and some left-leaning Latin American nations.
The OAS report concluded that without public documentary support for the election results announced, they could not be trusted and should not be recognised.
It comes as anti-government protests have turned violent with police firing tear gas to disperse protesters in the capital Caracas.
Three people have been killed and 44 injured in post election protests in Venezuela according to media reports.
Protesters took to the streets after Mr Maduro was declared winner of the disputed poll, including near the presidential Miraflores palace in Caracas.
Many staged "cacerolazo" demonstrations across the country, a traditional Latin American protest in which people bang pots and pans. Some who later marched took their pots and pans with them.
"I don't want gold, I don't want CLAP (the government food aid programme), I want Nicolas (Maduro) to leave," chanted protesters banging pots.
Many rode motorbikes and jammed streets or draped themselves in the Venezuelan flag, while others covered their faces with scarves as protection against tear gas.
In Caracas, heavily armed police sent protesters running when they fired tear gas to disperse a crowd, while other police erected barriers with long shields and batons.
In Coro, the capital of Falcon state, protesters cheered and danced when they tore down a statue depicting late president Hugo Chavez, Mr Maduro's mentor.
The Venezuelan Conflict Observatory said it had registered 187 protests in 20 states.
"I'll fight for my country's democracy. They stole the election from us," an unidentified protester told Reuters. "We need to keep on fighting for the youth."
Mr Maduro, in a live broadcast from the presidential palace, said his forces were acting against what he called violent protesters.
The armed forces have long supported Mr Maduro and there are no signs leaders were breaking from the government.
"We have been following all of the acts of violence promoted by the extreme right. I can tell the people of Venezuela that if they have done harm, we are acting," he said.
"We already know this movie, so once more, long with the civil, military and police union we are acting. We already know how they operate."
The Venezuelan Conflict Observatory said: "Numerous acts of repression and violence carried out by paramilitary collectives and security forces have been reported."
At least two people were killed in connection with the vote count or protests, one overnight in the border state of Tachira and another in Maracay yesterday.
Defence Minister Vladimir Padrino warned against allowing a repeat of the "terrible situations of 2014, 2017 and 2019". Anti-government protesters took to the streets those years and hundreds were killed.
Electoral authorities said that Mr Maduro had won a third term as president with 51% of the vote, extending a quarter-century of socialist rule.
However, the opposition said the 73% of voting tallies to which it has access showed its candidate Edmundo Gonzalez had won an unassailable victory, winning more than twice as many votes as Maduro.
Independent pollsters called Mr Maduro's claim of victory implausible, and governments in Washington and elsewhere immediately cast doubt on the results and called for a full tabulation of votes.
Uruguay's Foreign Minister Omar Paganini told CNN in an interview that his government will "never" recognise Mr Maduro as the winner, saying the opposition had clearly won.
Peru's government ordered Venezuelan diplomats in the Andean nation to leave within 72 hours, citing "serious and arbitrary decisions made today by the Venezuelan regime".
Peru is home to one of the largest communities of Venezuelan migrants, most of whom have fled their homeland in recent years.
Opposition leader Maria Corina Machado, who was barred from running in the poll, called in a post on X last night for supporters to march.
"My dear Venezuelans, tomorrow we meet; as a family, organised, demonstrating the determination we have to make every vote count and defend the truth," she said.
Jorge Rodriguez, a ruling party politician and Mr Maduro's campaign manager, urged government followers to take part in marches to the presidential palace to support the government.
While Mr Gonzalez has warned against violence, Mr Rodriguez accused the opposition of stoking violence.
Mr Maduro, a 61-year-old former bus driver and foreign minister, took office following president Hugo Chavez's death in 2013 and his 2018 election was considered fraudulent by the United States and others, who call him a dictator.
Mr Maduro has presided over an economic collapse, the migration of about a third of the population, and a sharp deterioration in diplomatic relations, crowned by sanctions imposed by the United States, the European Union and others which have crippled an already struggling oil industry.
