Masked gunmen opened fire on students returning from a march in which tens of thousands of Venezuelans denounced President Hugo Chavez's attempts to expand his power through constitutional changes.
Officials said at least eight people were injured Wednesday, including one by gunfire, at the Central University of Venezuela, or UCV -- the country's largest university.
Students protested in at least six other cities, and several turned violent with rock-throwing youths clashing with police shooting plastic bullets at demonstrators.
Photographers for The Associated Press saw at least four gunmen -- their faces covered by ski masks or T-shirts -- firing handguns at the anti-Chavez crowd at the UCV. Terrified students ran through the campus as ambulances arrived.
Antonio Rivero, director of Venezuela's Civil Defense agency, told Union Radio that at least eight people were injured, including one by gunfire, and that no one had been killed. Earlier, Rivero said he had been informed that one person had died in the violence.
The violence broke out after an estimated 80,000 anti-Chavez demonstrators -- led by university students -- marched peacefully to the Supreme Court to protest constitutional changes that would greatly expand Chavez's power if voters agree to the changes in December. Unrest, if it continues, could mar a Dec. 2 referendum on the controversial reforms.
Dozens of angry students surrounded a building where the gunmen were hiding, set fire to benches outside and knocked out windows with rocks. Later, armed men riding motorcycles arrived, scaring off students and standing at the doorway -- one of them firing a handgun in the air -- as people fled the building.
Justice Minister Pedro Carreno blamed students, university authorities, opposition parties and the media for the violence.
"We want to urge the media to reflect, to stop broadcasting biased news through media manipulation, filling a part of the population with hate," Carreno said in a televised address.
He did not provide details about the number of injured or if any suspects were arrested.
University students also staged demonstrations in the cities of Merida, Maracaibo, Puerto La Cruz, San Cristobal, Barquisimeto and Valencia on Wednesday.
The amendments being protested would abolish presidential term limits, give the president control over the Central Bank and let him create new provinces governed by handpicked officials.
The protesters demand the referendum be suspended, saying the amendments would weaken civil liberties and give Chavez unprecedented power to declare states of emergency.
"Don't allow Venezuela to go down a path that nobody wants to cross," student leader Freddy Guevara told Globovision during the march to the Supreme Court.
Chavez, who was first elected in 1998, denies the reforms threaten freedom. He says they would instead move Venezuela toward what he calls "21st century socialism."
In televised comments prior to the unrest, Chavez urged Venezuelans to turn out en masse to vote for the reforms. In reference to the opposition, he said: "Don't go crazy."
The Supreme Court is unlikely to act on the students' demands, given that pro-Chavez lawmakers appointed all 32 of its justices.