President Nicolas Maduro accuses them of being instruments of a "fascist" coup. They say they are exercising their rights by protesting insecurity, inflation and the arrest of fellow activists.

University students have taken center stage this week in Venezuela with volatile, headline-grabbing protest marches that challenged the government and wreathed Caracas and other cities in tear gas.

Building up steam in the provinces this month, the protests hit a boiling point in Caracas on February 12, when the largest anti-government demonstration since Maduro assumed office nearly a year ago degenerated into street violence that left three dead, more than 60 injured and dozens under arrest.

The protests were initially a reaction to rising crime and personal insecurity in Venezuela, a country with one of the world's highest murder rates.

Daniel Martinez, president of the Federation of Student Centers of Simon Bolivar University in Caracas, said the country's university campuses have been particularly vulnerable, "with armed attacks, assaults, rapes and kidnappings."

Added to that is a deteriorating quality of life, with 56 percent inflation, and widespread shortages of food and other basic necessities. Finally came the jailing of students in a crackdown by security forces in the provinces.

Maduro has denounced the protests as "a coup d'etat in the making" and claims the students are infiltrated by rightwing extremists linked to the opposition.

But Juan Requesens, head of the Federation of University Centers of the Central University of Venezuela, insisted that "the student movement is not about toppling governments."

"We are willing to sit down with the government once our colleagues are released. We want to dialogue to resolve our demands," he added.

Over the past two weeks, the students have been joined by some prominent opposition leaders who have encouraged a campaign of street protests under the slogan "the exit."

Best known are the leader of the Popular Will party, Leopoldo Lopez, the mayor of the Caracas metropolitan area Antonio Ledezma and Maria Corina Machado, an opposition member of the National Assembly.

After Wednesday's violence, Maduro ordered Lopez's arrest for homicide and inciting violence.

So far, the arrest order has not been carried out, however, and Lopez has taunted the president via Twitter.

But the confrontational strategy has been questioned within the opposition alliance.

Foremost among those expressing reservations is the opposition's candidate in the last presidential elections, Henrique Capriles, who warned that "the conditions are not present to pressure for the government's exit."

- Day of bloodshed -

On Wednesday, clashes erupted at the end of a student protest when radicals, some wearing masks, vandalized the attorney general's office in Caracas.

Running battles erupted between students, riot police and groups with government insignia and spread to other parts of the city, leaving three dead and dozens more injured or under arrest.

"The students have the right to demonstrate. But there is no right for small groups of infiltrators to provoke death and violence," Vice President Jorge Arreaza said Saturday on state-run VTV television.

He said no more than 500 to 600 people were taking part in the street clashes.

- 'Mexican fiesta' -

This week, Interior and Justice Minister Miguel Rodriguez Torres accused some of the student movement's leaders by name, claiming they were part of a "conspiratorial tactic to generate chaos and violence" and alleging they had been trained in Mexico to carry out acts of violence.

"One of the most important meetings to prepare these groups... took place in Mexico and was dubbed 'Mexican fiesta,'" he said.

Gabriela Arrellano, a student leader from the University of the Andes who was among those named by Rodriguez, vehemently denied the accusation.

"Rodriguez Torres should stop lying at the same time that he talks about dialogue," she told AFP.

"I have never been in Mexico. Enough with the conspiracy theories. This is a student movement that is demanding its rights."

The government has also accused the students of sowing chaos by blocking roads, especially during rush hour in Caracas, a city choked with traffic at the best of times.

"Yes, it's true, the demonstrations result in roads being blocked, but the student movement has various ways of expressing itself when the government doesn't want to listen," Requesens said.