Clash between riot police and angry protesters marks the latest violence in nearly two months of unrest in which 58 people have died.
Riot police in Venezuela fired tear gas and water cannon to stop anti-government protesters from marching on a key military installation on Friday.
The opposition is trying to sway the support of the armed forces, a key pillar of the government of socialist President Nicolas Maduro, who is resisting opposition calls for early elections.
Retired military personnel joined demonstrators who tried to march to the Los Proceres complex, which houses the defence ministry and lies close to a major military base in Caracas.
Friday's protest was aimed at "demanding that the armed forces lower their weapons and not be complicit in the dictatorship," said Freddy Guevara, an opposition leader who is vice president of parliament, the only branch of government the opposition controls.
He called on the military to reject a "constituent assembly" to be elected in July and tasked with drafting a new constitution, saying Maduro's plans "will liquidate Venezuelan democracy forever."
Death toll rises
Masked protesters threw Molotov cocktails at riot police in scenes familiar after nearly two months of unrest.
A 33-year-old man who was injured Thursday night during a protest in the western city of Cabudare died on Friday, bringing the death toll from eight weeks of unrest to 58.
Several people were also injured in the capital on Friday, including opposition lawmaker Carlos Paparoni, who was struck in the leg with a blunt object.
Attorney General Luisa Ortega blamed military police for hundreds of injuries and at least one death.
Protesters brand the socialist president a dictator, blaming him for economic turmoil and food shortages.
Maduro is resisting their calls for early elections, saying the opposition and the United States are plotting a coup against him.
Despite the opposition's calls for the military to abandon Maduro, the high command has retained its public support for him so far.
The president has launched steps to reform the constitution in response to the crisis. His opponents say that is a bid to dodge elections and cling to power.