"Prosecutor's office Nr. 1 in Miranda is investigating the death of Ronney Tejera (24) and 3 injured during a demonstration in Los Teques [neighborhood] this July 20," the Public Ministry tweeted.
The Nacional news website reported the victims had been fired at by grassroots militia supporting the government of President Nicolas Maduro.
Nearly a hundred people, most of them protesters, have lost their lives since anti-government demonstrations swept the oil-rich South American nation in early April.
Opposition activists accuse President Maduro of mismanagement and demand that he drop his plans for a new legislative body and call an early election. His term expires in 2019.
A 24-hour general strike organized by Venezuelan opposition began in the country on Thursday in an attempt to put pressure on the government.