Venezuelan troops blocked students marching against President Nicolas Maduro on Thursday as pro-government supporters also rallied on the anniversary of 2014 protests that led to 43 deaths.
National Guard soldiers and police fired teargas and buckshot in the volatile western city of San Cristobal against demonstrators tossing rocks and Molotov cocktails.
Witnesses and authorities said five security officials and three demonstrators were hurt in the nearly two-hour standoff, and that some shops were vandalized and four students arrested.
In Caracas, troops cordoned off several hundred students on an unauthorized march to a church where they planned a mass in honor of demonstrators who died. Instead, a priest came out and said brief prayers in the open air.
Also in the capital, thousands of red-clad supporters of Maduro, the successor to late socialist leader Hugo Chavez who died of cancer in 2013, held a much larger rival rally.
Mindful of nearly four months of clashes last year, when thousands took to the streets demanding Maduro's resignation and protesting over the OPEC nation's faltering economy, some Caracas residents stayed at home to avoid trouble.
"We are marching peacefully to honor those who fell," said Fabio Valentini, 21, a pro-opposition student from Andres Bello Catholic University who was on the streets last year when the first victims were shot dead.
"Venezuela, today, is in a far worse situation than last year," he added. "The economy is in crisis. Crime is worse. Our aim is not to topple the regime, but to demand rights and changes to failed policies."
Maduro says opposition radicals sought to carry out a coup in 2014, and still harbor the same ambition.
"Where did they get the stones, sticks, pipes and bottles to attack our officials?" said local military boss General Jose Morantes in San Cristobal. "Once again, we see terrorist plans to turn a peaceful march into violence within seconds."
Student leaders there blamed infiltrators for the trouble.
Venezuelans are suffering shortages, long shopping lines, high inflation and a recession exacerbated by the plunge in crude revenues. Parliamentary elections looming for the end of 2015 are adding to national tensions.
"Oil prices will rise again and we'll be ok," said Javier Castillo, 20, a student at the Bolivarian University among thousands of singing, dancing and banner-waving Maduro supporters at the rally in Caracas' Plaza Venezuela.
"We on the Left are people of peace, happiness and harmony," he said. "Those on the far Right are the ones seeking violence. Let those bitter mummy's and daddy's boys come here and see the joy."
Jailed protest leader Leopoldo Lopez, who spearheaded last year's protests before being arrested, sent a message from jail.
"The fight continues," he said via a Twitter account run by his wife. "If you tire, you lose."
Both the government and opposition supporters blame each other for the 2014 deaths. Security officials, Maduro supporters and protesters were among the victims.