Venezuelan opposition leader María Corina Machado has denounced what she says are attempts by the government to intimidate her and her supporters.
She said two campaign co-ordinators had been “abducted” and party offices had been vandalised.
The incidents come just months after the government agreed to a deal laying the groundwork for free and fair elections to be held in 2024.
Ms Machado said Tuesday’s incidents violated that deal.
Under the agreement, which was reached in Barbados in October last year, the government of President Nicolás Maduro committed to allowing international observers to monitor the presidential poll, which is scheduled for a yet-to-be-determined date in the second half of 2024.
The 2018 election, which saw President Maduro win a second term in office, was widely dismissed as neither free nor fair.
As part of the Barbados deal, his government also promised to guarantee that all candidates would be able to freely and safely move throughout the country.
In return, the United States, which backed the Barbados talks, eased some of the sanctions it had imposed on Venezuela’s oil sector.
However, just three months after the agreement was struck, tension between the opposition and the government is again on the rise.
On Monday, Venezuela’s Attorney-General Tarek William Saab, a close ally of President Maduro, announced that 32 people had been arrested for allegedly plotting to assassinate the president and Venezuela’s defence minister, Vladimir Padrino.
Mr Saab also said that arrest warrants had been issued for another 14 suspects, among them human rights activist Tamara Sujú and journalist Sebastiana Barráez, who both live outside of Venezuela and have been highly critical of the government.
Tension also seems to be on the rise again with the United States, with Mr Padrino claiming that the alleged plot to kill him and the president had the backing of the CIA and the US Drug Enforcement Administration (DEA).
The US state department said on Tuesday it was “deeply concerned” by Monday’s arrests.
“Actions that run counter to the spirit and the letter of the Barbados Agreement will have consequences,” state department spokesman Matthew Miller warned.
Meanwhile, rival groups of supporters took to the streets of the capital Caracas on Tuesday.
President Maduro appeared to goad his followers when he told them, invoking independence hero Simon Bolívar: “If the fascists ever hurt me (…), I leave it to you to do what you have to do to restore justice and peace in Venezuela. Activate the Bolivarian fury!”
Graffiti appeared later on the pavement in front of María Corina Machado’s campaign headquarters reading “Bolivarian fury”.
The whereabouts of two of her campaign co-ordinators are unknown after video showed men seizing them and taking them away in unmarked cars.
Ms Machado asked for help from the international community, telling them that “we must put a stop to this madness because this is what the Bolivarian fury means: aggression, disappearances, persecution”.
The 56-year-old politician overwhelmingly won an opposition primary held in October despite being banned from running for office.
She has appealed against the ban, which she has always maintained was unfair and designed to keep the opposition down.
Mr Maduro has not yet announced whether he will stand for re-election or if his party will put forward a different candidate.