Tomas Frias University Rector Pedro López told Radio Panamericana that the students had gathered to elect new student body leaders at the school in the mountainous city of Potosi, some 420 kilometers (260 miles) south of La Paz, the capital, AP reported.
“In the middle of the assembly, a tear gas grenade was detonated, which created a stampede,” he said. “Many students were trampled.”
Col. Limberth Choque, Potosi's police chief, told state television that all four of the dead were female.
Police said that the suspect, also a student at the university, has been arrested. They did not release his identity or comment on possible motives.
President Luis Alberto Arce Catacora expressed his condolences to the victims.