A student leader was fatally shot in the western university city of San Cristobal after a long day of street clashes in which Venezuelan security forces attacked and dismantled barricades at key intersections, according to the city's mayor.

Local TV reporter Beatriz Font said there were unconfirmed reports of at least two others wounded by gunfire after dark on Monday in the city of 600,000 people where student-led protests erupted last month and where anti-government unrest has been fiercest.

The human rights group PROVEA tweeted that one student was seriously wounded by a bullet.

National Guardsmen firing tear gas and plastic shotgun pellets had battled protesters all day in residential neighborhoods, Font told the Associated Press news agency.

The slain student leader, Daniel Tinoco, was shot in the chest after dark, San Cristobal Mayor Daniel Ceballos said on Twitter. The opposition politician did not say who might have killed Tinoco, but tweeted that armed paramilitaries allied with the government known as "colectivos" had battled protesters along with the National Guard.

Font said Tinoco was "one of the students who was always out on Carabobo Avenue [manning barricades] giving interviews. He was really enthusiastic."

Earlier in the day, the mayor had said the clashes were disrupting life in San Cristobal.

"Here the city is pretty well paralysed," Ceballos told AP.

First foreign death

Also on Monday, a Chilean woman was shot dead while clearing a barricade put up by anti-government protesters, the first foreign fatality during a month of civil unrest in Venezuela, authorities said.

The deaths of Gisela Rubilar, 47, who was studying in the western Venezuelan city of Merida, and of a protester shot in the border state of Tachira, has brought the number of fatalities in five weeks of unrest to at least 22, Reuters news agency reported.

"She was ambushed by extreme right-wing groups ... She was vilely murdered with a shot in the eye," Alexis Ramirez, the governor of Merida state, told reporters, blaming the killing of Rubilar on unidentified demonstrators in the Andean city.

Students and opponents of President Nicolas Maduro have been maintaining street barricades in various cities since last month, demanding the president's resignation and solutions to problems of rampant crime and economic shortages.

The barriers have become frequent flashpoints for violence between protesters, police and government supporters.