Four lawmakers were injured. One of them, Americo de Grazia, had to be taken in a stretcher to an ambulance suffering from convulsions, said a fellow congressman.
"This doesn't hurt as much as watching how every day how we lose a little bit more of our country," Armando Arias said from inside an ambulance as he was being treated for head wounds that spilled blood across his clothes.
The attack, in plain view of national guardsmen assigned to protect the legislature, comes amid three months of often- violent confrontations between security forces and protesters who accuse the government of trying to establish a dictatorship by jailing foes, pushing aside the opposition- controlled legislature and rewriting the constitution to avoid fair elections.
"We still haven't finished definitively breaking the chains of the empire," El Aissami said, adding that President Nicolas Maduro's plans to rewrite the constitution - a move the opposition sees as a power-grab - offers Venezuela the best chance to be truly independent.
After he left, dozens of government supporters set up a picket outside the building, heckling lawmakers with menacing chants and eventually invading the legislature themselves. Despite the violence, lawmakers approved a plan by the opposition to hold a symbolic referendum on July 16 that would give voters the chance to reject Maduro's plans to draft a new political charter.