Soldiers used tear gas, plastic bullets and water cannons to scatter tens of thousands of demonstrators protesting constitutional reforms that would permit Venezuelan President Hugo Chavez to run for re-election indefinitely.
Led by university students, protesters on Thursday chanted "Freedom! Freedom!" and warned that 69 amendments drafted by the Chavista-dominated National Assembly would violate civil liberties and derail democracy.
It was the biggest turnout against Chavez in months, and appeared to revive Venezuela's languid opposition at a time when the president seems as strong as ever. Students promised more street demonstrations over the weekend, but no opposition-led protests were planned for Friday.
"This is a dictatorship masked as democracy," said Jorge Rivas, an 18-year-old student. "Chavez wants our country to be like Cuba, and we're not going to allow that to occur."