Venezuelan President Nicolas Maduro responded Saturday to ongoing opposition protests with a counter-demonstration by thousands of his supporters.
President Maduro used the pro-government rally in Caracas to denounce opposition leader Leopoldo López.
Police have issued an arrest warrant for López for organizing anti-government protests Wednesday that led turned violent. Three people were killed, including two opposition protesters.
Mr. Maduro called López a "fascist" and a "coward" Saturday and urged him to turn himself in.
U.S. Secretary of State John Kerry says Lopez's arrest warrant has a chilling effect on the rights of Venezuelan citizens to peacefully express their grievances.
In a statement, he said the Venezuelan government is obliged to protect the fundamental freedoms and safety of its citizens.
Venezuelan forces used tear gas and water cannons against hundreds of student protesters Friday, angry at Mr. Maduro for soaring inflation, shortages in supermarkets, and rampant crime.
Nearly 100 people have been arrested in the past week of protests.