The clashes come as President Nicolás Maduro has ordered security forces and armed civilian militias onto the street on the same day that the opposition is staging "the mother of all marches".
Maduro, addressing supporters at a larger countermarch, seemed open to some sort of electoral showdown.
Security forces used tear gas to disperse the anti-government demonstrators who had gathered in the hundreds of thousands in Caracas for a protest dubbed the "mother of all marches".
A short block away, a sea of red-shirted government supporters marched by calmly, some dancing to a salsa band that tried to provide an air of normalcy to the otherwise tense political standoff that has paralyzed Venezuela the past few weeks.
Citing witnesses in Caracas, Reuters reports that Carlos Moreno, a teenage student who had not planned to join the demonstration, was shot in the head after "government supporters approached an opposition gathering and fired shots". Opposition leaders also said a young man was shot in the head at a protest and rushed to the hospital.
"The US government, the state department, have given the green light, the approval for a coup process to intervene in Venezuela", Maduro said in a televised address Tuesday, according to The Guardian.
Venezuela suffered its last major wave of unrest in 2014 when 43 people were killed in anti-government riots. The remaining 59 percent of Venezuelans say they are "struggling". In many cases protests have ended with youths throwing rocks squaring off against security forces spraying tear gas in melees that have dragged on well into the evening. She also wrote that "these governments misuse global law to back interventionism in Venezuela to attempt to govern the country from abroad". Venezuela's Supreme Court abandoned measures to seize power from the opposition-controlled legislature after the moves drew worldwide condemnation and raised pressure on President Nicolas Maduro. Opposition leaders also accuse the government of infiltrating marches with violent protesters as a way of discrediting them.
Colombia and 10 other countries asked Venezuela to "guarantee" its people's right to protest on Monday as five people have already been killed in ongoing anti-government protests.
"We're a peaceful people, but we're also armed", he said.
Late on Monday, 11 regional powers including Argentina, Brazil and Mexico bewailed the deaths of several protesters in recent clashes. The military has also vowed its full support to Maduro.
Maduro blasted Borges for urging a "coup" against him, and said the opposition lawmaker "should be put on trial".
In the same poll, 91 percent of Venezuelans said the country's economy is "getting worse", compared to 5 percent who said the economy is "getting better". The opposition says this is because the ruling Socialist Party is likely to fare poorly in such a vote.
"Today the people stood by Maduro!" the president said, blasting his rivals as "anti-Christs".
Addressing a socialist rally on Monday, Maduro announced he would begin expanding the ranks of the National Bolivarian Militia, a creation of late dictator Hugo Chávez meant to arm radical socialists in a nation where legally owning firearms outside of such groups is banned.
In addition to Caracas, social media reported massive demonstrations in provincial cities, including Merida, Maracaibo, Valencia and San Cristobal. "Every time we do something, that's what we feel: that the worst thing would be to stay home, let fear take over us".