Authorities are investigating the fatal shooting of a student protester at the University of Zulia, in western Venezuela, amid escalating tensions between the nation’s socialist president, Hugo Chávez, and opponents of his government’s proposed constitutional reforms.

The student was part of a group marching to the office of the rector of the public university on Friday, when gunmen started shooting from a pair of passing cars. Besides the slain student, 10 others, along with a passerby, were injured. One of the gunmen was also killed and a second injured, apparently by their own crossfire. Classes were suspended until at least Wednesday.

The shootings came amid mounting student-led protests across the nation against the proposed reforms. The constitutional revisions include the elimination of presidential term limits, curbs on press freedoms during government-declared states of emergency, and changes in university election rules that would increase the government’s influence in public institutions still dominated by opponents of Mr. Chávez’s policies.

University students have led protest marches, some of which have ended in violence. Student leaders and government officials have traded accusations over who is to blame for the violence.

On Sunday, in his regular weekly call-in show, Mr. Chávez railed against the protesters, whom he said included “disguised students” and “the rich classes.” He also warned that the government might discontinue issuing permits for opposition marches. He ordered investigations of the protest leaders.

In recent actions affecting education, Mr. Chávez has imposed a socialist curriculum on the nation’s elementary and secondary schools, and has scrapped entrance examinations at public universities in an effort to increase university access to students from poor families. —Mike Ceaser