Opponents and supporters of Venezuela's President Nicolás Maduro planned to rally on Tuesday as protests and clashes spread after a weekend election in which the long-ruling socialist was named the winner despite opposition claims of a landslide victory.

Renewed instability in the South American oil producer brought divided international reaction: the United States said Maduro's re-election had no credibility and was mulling more sanctions, while China and Russia congratulated him.

Protests began after the election board declared on Monday that Maduro had won a third term with 51 per cent of votes to extend his "Chavista" movement's quarter-century rule.

The opposition, which considers the election body in the pockets of a dictatorial government, said the 73 per cent of vote tallies to which it has access showed its candidate, Edmundo González, had more than twice as many votes as Maduro.

'We are tired of this government'

Many Venezuelans staged "cacerolazos," a traditional Latin American protest where people bang pots and pans in anger.

Some blocked roads, lit fires and threw petrol bombs at police as protests proliferated, including near the Miraflores presidential palace in the capital, Caracas.

"We are tired of this government, we want a change. We want to be free in Venezuela. We want our families to return here," said one masked protester, referring to the exodus of about a third of Venezuelans in recent years.

"I'll fight for my country's democracy. They stole the election from us," said another.

Police with shields and batons in Caracas and the city of Maracay fired tear gas to disperse some protests.

Many demonstrators rode motorbikes and jammed streets or draped themselves in the Venezuelan flag. Some covered their faces with scarves as protection against tear gas.

Maduro blames 'extreme right'

The government calls them violent agitators.

"We've seen this movie before," said Maduro from the presidential palace, pledging that security forces would keep the peace. "We have been following all of the acts of violence promoted by the extreme right."

The armed forces have long supported him and there were no signs generals were breaking from the government.

In Coro, capital of Falcon state, protesters cheered and danced when they tore down a statue depicting former president Hugo Chávez, Maduro's mentor who ruled from 1999 to 2013.

A local monitoring group, the Venezuelan Conflict Observatory, said it had registered 187 protests in 20 states by 6 p.m. local time on Monday, with "numerous acts of repression and violence" carried out by paramilitary groups and security forces.

At least two people were killed in connection with the vote count or protests, one in the border state of Tachira and another in Maracay.

Economic collapse

Maduro, a 61-year-old former union leader and foreign minister, won election after Chavez's death in 2013 and was re-elected in 2018. The opposition said both votes were rigged.

He has presided over an economic collapse, mass migration and deteriorating relations with the West, including U.S. and EU sanctions that have crippled an already struggling oil industry.

Defence Minister Vladimir Padrino warned against allowing a repeat of the "terrible situations of 2014, 2017 and 2019," when waves of anti-government protests led to hundreds of deaths and failed to dislodge Maduro.

WATCH | Maduro declared president in disputed Venezuela election:

Maduro declared president in disputed Venezuela election

Venezuela's incumbent leader, Nicolás Maduro, was declared the winner in a disputed presidential election that the opposition says was stolen from them.

Independent pollsters called Maduro's victory implausible, while governments in Washington and elsewhere in Latin America questioned the results and urged a full tabulation of votes.

"Not even [Maduro] believes the electoral scam he is celebrating," said Argentina's President Javier Milei.

Peru ordered Venezuelan diplomats to leave within 72 hours, citing "serious and arbitrary decisions made today by the Venezuelan regime."

Call for marches

But in a familiar global division, allies including Russia, China and leftist-led Latin American nations backed Maduro.

"China will, as always, firmly support Venezuela's efforts to safeguard national sovereignty, national dignity and social stability, and firmly support Venezuela's just cause of opposing external interference," Chinese President Xi Jinping said in a message of congratulation.

Venezuelan opposition leader María Corina Machado, who was barred from running in the election but has spearheaded the campaign for González, called for marches on Tuesday.

"My dear Venezuelans, tomorrow we meet; as a family, organized, demonstrating the determination we have to make every vote count and defend the truth," she said.

The government is also planning pro-Maduro rallies, with many Venezuelans fearing another bout of violence and bloodshed similar to others in its turbulent recent history.