Venezuela's opposition leader Henrique Capriles has tried to defuse the country's heated political situation after clashes left seven people dead in the aftermath of last week's controversial presidential elections.

Capriles distanced himself from the political violence and called off a rally to demand a recount of the vote, which was won with a 1.8 percent margin by late president Hugo Chavez's heir Nicolas Maduro.

"To all my followers ... this is a peaceful quarrel. Whoever is involved in violence is not part of this project, is not with me," Capriles said.

Maduro and Capriles traded accusations after a number of opposition demonstrations across Venezuela turned violent earlier this week.

"Whoever goes out into the street tomorrow is playing the Government's game," Capriles said.

"The Government wants there to be deaths in the country," he added, claiming that Maduro's administration plans to infiltrate the rallies to turn blame for the violence onto him.

Protesters have taken to the streets in Caracas and other major cities, including Barinas, Merida in the west, and Maracay in the central industrial heartland, after the National Electoral Council confirmed Maduro as election winner and dismissed Capriles' calls for a vote-by-vote recount.

Clashes between demonstrators and police left seven people dead and more than 60 injured, while another 139 were arrested, Attorney General Luisa Ortega said.

A pro-government gang of motorcycle thugs rampaged through the centre of the northern city of Los Teques and tossed a firebomb into an opposition party office, AP reported.

Opposition leader Capriles, who is also governor of the state of Miranda, said Maduro is using violence to divert attention from election irregularities.

Thousands of ballots casted for Capriles did not appear in the official tally, the opposition claims.

Maduro claimed protests were part of a US-backed coup d'état and blamed the deaths on "neo-Nazi gangs" supporting Capriles.

"This is the responsibility of those who have called for violence, who have ignored the constitution and the institutions,"Maduro said in a televised speech.

"If they want to overthrow me, come get me. With the people and the armed forces, I am here," he added.

Interior Minister Nestor Reverol accused Capriles of insurrection and civil disobedience.