"The interviews conducted remotely by the UN Human Rights team paint a picture of widespread and systematic use of excessive force and arbitrary detentions against demonstrators in Venezuela".
Venezuela's supreme court sentenced a prominent opposition mayor, Ramon Muchacho, to 15 months in prison and stripped him of his right to hold political office.
He has defied worldwide condemnation , including from the UK, America and the United Nations, and has presided over three-digit inflation and a shortage of food and medicine.
According to media reports, President Nicolás Maduro has since declared victory in elections for a Constituent Assembly convened by him.
Ten others fled when the gunfight began, and are being hunted down.
The country's defense minister and head of the armed forces, General Vladimir Padrino, addressed the Constituent Assembly in uniform.
The Venezuelan army on Tuesday blocked opposition lawmakers from entering the Legislative Palace as that country's political crisis intensifies.
The decree giving the body its powers was unanimously approved, said the ruling socialist party's leader, Delcy Rodriguez.
Earlier on Tuesday, the United Nations slammed Venezuela for the use of excessive force against anti-government protesters.
"Witness accounts suggest that security forces, mainly the National Guard, the National Police and local police forces, have systematically used disproportionate force to instil fear, crush dissent, and to prevent demonstrators from assembling, rallying and reaching public institutions to present petitions", the rights office said in a statement.
The judges convicted another mayor on Tuesday for failing to move against protesters during four months of political unrest.
The opposition is struggling to regain its footing since last week's seating of a loyalist special assembly, which is now busy rewriting the country's constitution. As a counter to the Peru meeting, he was hosting a meeting of foreign ministers from the Bolivarian Alliance, a leftist coalition of 11 Latin American nations. On Monday, the president of neighbouring Colombia, Juan Manuel Santos, has brandished the threat of a rupture of diplomatic missions.
Inflation in Venezuela's crisis-hit economy quickened to 248.6 percent in the first seven months of the year, the opposition-led congress said on Wednesday in the absence of official data.
President Nicolas Maduro summoned the constitutional assembly in what he contends is an attempt to resolve the nation's political standoff, but opposition leaders insist it is a power grab.
The assembly was expected to gather at the legislative palace in Caracas for the first time since voting Saturday to remove the nation's outspoken chief prosecutor, a move that drew condemnation from numerous same regional government that are sending representatives to the meeting in Peru's capital. It gathered foreign ministers and representatives from Cuba, Bolivia, Ecuador and Nicaragua, and a number of Caribbean nations that receive cheap Venezuelan oil.
Venezuela's military was still searching for the group after two were killed and eight captured in the raid.
Since the disputed election, security forces have stepped up their presence.
Those who attacked the base near the city of Valencia said their operation was aimed at starting an insurgency against theleftist Maduro.
"You can expect new incidents to occur as this unease grows", he said. "The dictatorship has its days counted", transmitted the hackers.