Protests have erupted in cities across Venezuela after election officials said the president's opponents had failed to force a referendum on his future.
Protesters believe the government is ignoring the poll result
At least one demonstrator was killed in clashes with the security forces in the capital, Caracas.
The National Electoral Council said only 1.8m signatures calling for a referendum had been verified, but another 870,000 were disputed.
The opposition needs 2.4m to force the vote on leftist President Hugo Chavez.
It could still reach this target - the council has said it will publish lists of the disputed signatures and set up posts where people who find themselves on these listings can go and validate their entry.
But the opposition has accused the president of trying to prevent a referendum and the electoral council of favouring him.
Senior opposition figures have already said they will not accept the electoral commission's plans for voters to confirm their signatures, complaining this was not included in the initial rules for the referendum.
"There is no other way but to accept this decision," responded election official Francisco Carrasquero. "If someone does not accept it, they will be acting outside the law."
Soldiers in armoured carriers maintained a stand-off with anti-Chavez protesters in several cities across Venezuela, including Valencia, Barquisimeto and Maracaibo.
Witnesses report petrol bombs, stones and tear-gas shells flying across improvised barricades of burning tyres.
Hugo Chavez's supporters say he has helped the country's poor
The government urged opposition mayors to end the rioting.
"It's amazing to see how some mayors are allowing the destruction of their own municipalities," said government security official Carlos Valter Bettid.
Venezuelans who backed the plebiscite against President Chavez have been protesting for days.
They were told on Tuesday it could take three weeks for more signatures to be gathered to confirm the poll result.