A group of masked assailants has attacked a leading university in the Venezuelan capital, torching two buses and seriously damaging its rectory building, The Associated Press reported.

Amalio Belmonte, the secretary-general of the Central University of Venezuela, said about 20 people invaded the campus and shot firearms into the air Wednesday, June 19 afternoon.

Belmonte said they set one bus on fire near the entrance to a study center and another outside the ground floor of the offices of the rectory. The fire from the second vehicle burned for more than a half-hour and damaged the building, plus important works of art.

Belmonte believes the attack was revenge for student protests that since June 7 have been demanding pay raises for professors and more funds for the university’s budget.

A firefighter said nobody was hurt.