JOHANNESBURG (AP) — South African police have fired rubber bullets and set off stun grenades to disperse student protesters on a university campus in Johannesburg.

The clash occurred Tuesday at the University of the Witwatersrand, which had announced it was re-opening after closing because of sometimes violent demonstrations for free education.

Adam Habib, the university's vice-chancellor, had said police and private security guards would be on campus to help "take back our campus" on behalf of staff and students who wanted to return to class.

President Jacob Zuma has said the recent protests at some South African universities have caused about $44 million in property damage and threaten to sabotage the country's system of higher education.

The government says it will cover the 2017 fee increases of many students who have limited resources.