Venezuelan police made about 80 arrests and fired tear gas at anti-government student protesters who hurled stones and fireworks at a ministry building in the capital.
The students, who were marching to demand the release of protesters arrested in recent days, massed in eastern Caracas but the demonstration quickly became violent when they targeted the Tourism Ministry and riot police intervened.
Local non-governmental group Foro Penal later disputed the official account, saying it had tallied 105 arrests, including minors. Police did not immediately confirm the figure.
Trucks carrying the detainees tried to move along the main route of the Caracas district of Chacao, heart of more than three months of opposition protests, amid a crowd shouting "Let them go!"
Last week, more than 200 people were arrested in police raids on encampments of protesters in Caracas. Most have since been freed.
"Fewer and fewer people are heeding protest calls. Intimidation has succeeded," one of the young marchers told AFP, requesting anonymity after a previous arrest.
At least 42 people have died and more than 800 have been injured since students and other opponents of the socialist government took to the streets in February to protest rampant crime, runaway inflation and shortages of basic goods.
