Protests have erupted on the streets of Venezuela as the opposition demand early elections to oust Nicolas Maduro.
It was the first coordinated street demonstration called by the opposition since Maduro launched a crackdown with the arrests of several of his opponents early this month.
The protest came amid high tension in the South American oil-exporting country, where food and medicine shortages have sparked riots and looting over recent months.
Security forces blocked around 2,000 opposition supporters from marching to the headquarters of the National Electoral Board in Caracas.
The area was the scene of scuffles in demonstrations last year but no major incidents were reported on Monday.
Similar marches were called across the country by the opposition MUD coalition.
"I came because I want elections to be held," said Dora Valero, a 63-year-old retired nurse who marched in eastern Caracas.
"It is the best way to get rid of this government that has gotten us into such a bad situation."
Several thousand supporters of Maduro dressed in red gathered elsewhere in central Caracas.
They defended Maduro and the socialist "revolution" launched by his predecessor Hugo Chavez.
"The people are in the street supporting the president," said one demonstrator, Pedro Camargo. "We will not let them end our revolution."
The center right-dominated coalition has declared Maduro unfit for office due to his handling of the crisis, sparked by falling prices for Venezuela's crucial oil exports.
But the socialist president has overruled all their efforts to hold a vote on removing him from office over the past year.
He says the crisis is the result of a US-backed capitalist conspiracy.
Monday's allies raised fears of unrest in Venezuela, where anti-government riots left 43 dead in 2014.
"The government is afraid that there will be a chain reaction in the street due to the terrible economic situation, which could create a perfect storm that gets out of its control," said Venezuelan analyst Diego Moya-Ocampos, of research group IHS Markit Country Risk in London.
Vatican-backed talks broke down last month and show no signs of restarting despite fresh efforts by mediators in recent days.
The opposition insists elections are the only way forward.
Municipal and regional elections are due this year, but no date has yet been set.
The next scheduled general election is set for late 2018, with Maduro's current term expiring in early 2019.
That is too long a wait for the opposition.
"We want to be able to choose," said the opposition speaker of congress, Julio Borges. "It is up to us to achieve that."
The opposition chose a symbolic date for its protest: January 23, 1958 saw the end of a military dictatorship in Venezuela.
A Spanish journalist, Aitor Saez, said on Sunday that Venezuelan authorities had deported him when he tried to enter the country to cover the protests for German broadcaster Deutsche Welle.
He was the latest of several foreign reporters to have reported being turned away from the country in recent months.