The Venezuelan defence minister has described anti-government protests which erupted after the disputed election result was announced as « a coup ».
People took to the streets across cities and towns in Venezuela on Monday in protest after the government-dominated electoral authority had declared President Nicolás Maduro the winner of the election.
Two leading NGOs in Venezuela have said that there have been several deaths and dozens of people injured.
As people gathered for fresh protest rallies, Gen Vladimir Padrino read out a statement saying that President Nicolás Maduro had the « absolute loyalty and unconditional support » of the armed forces, which would « defeat the coup ».
Venezuela’s attorney general, who is a close ally of Mr Maduro, said a member of the military had been killed in the anti-government protests.
Attorney General Tarek William Saab added that 749 people had been arrested.
He told journalists that most would be charged with « resisting authority and, in the most serious cases, terrorism ».
The opposition Voluntad Popular (Popular Will) party said among those who have been detained was their national political co-ordinator, Freddy Superlano.
The party warned that the government was stepping up its repression of activists who have been demanding the publication of results from polling stations, which the opposition say prove that their candidate won.
Protest erupted after the head of the National Electoral Council (CNE) – who is a member of Mr Maduro’s party and used to work as his legal adviser – declared the president re-elected for a third consecutive term.
The CNE had earlier announced that Mr Maduro had won with 51% of the votes, ahead of Edmundo González with 44%.
However, the electoral authority has so far failed to publish detailed voting tallies, which the opposition says show that the result the CNE announced was fraudulent.
The regional body for the Americas, the Organization of American States (OAS), has accused Venezuela’s government of completely distorting the results.
The opposition coalition backing Mr González said they had been able to review 73.2% of the voting tallies and maintained that they confirmed that Mr González was the winner by a wide margin.
« We have the records showing our categorical and mathematically irreversible victory, » Mr González said.
Opposition parties had united behind Mr González in an attempt to unseat President Maduro after 11 years in power, amid widespread discontent.
Almost 7.8m people have fled the economic and political crisis which has rocked the country under the Maduro Administration.
On Monday, crowds of people chanted “freedom, freedom” and called for the government to fall.
In some areas, posters of President Maduro were ripped down and burned while tyres, cars and rubbish were also set alight.
Miguel Sarzalejo, 64, told the BBC that “we want a better future for the youth because if not they will leave the country ».
« We have a rich country and he is destroying everything, » he added referring to President Maduro.
The opposition has urged its supporters to gather peacefully in squares across the country on Tuesday while the government has also called on its backers to rally.
The spokesman for the United Nations Secretary-General, Stephan Dujarric, said Venezuelans must be allowed to exercise their right to peaceful protest.
« It’s important that all political leaders and their supporters reject all forms of violence, threats of violence or incitement to violence. It is also, as it is in every country, primordial that the authorities respect the right of people to demonstrate peacefully and that they should protect that right and not hinder it. »
By Ione Wells in Caracas and Vanessa Buschschlüter in London – BBC News