Police fired stun grenades and teargas at students who hurled rocks at them at Fort Hare university in the Eastern Cape province on the eve of the festivities, the national broadcaster and an independent news agency reported.

“This morning students tried to barricade the roads leading to the university,” police spokesman Khaya Tonjeni told AFP.

“We have reinforced the security because there was a high level of intimidation two days ago, the marquees were burnt,” he said.

The violence at Fort Hare follows protests at campuses across South Africa over the past year by students with a range of demands over issues such as fees and accommodation.

Several universities were closed briefly in February after a wave of protests in which buildings were torched, while an auditorium was firebombed at the University of Johannesburg earlier this week.

President Jacob Zuma is scheduled to give a keynote address at the Fort Hare celebrations, where Mugabe is also expected to speak.

Fort Hare was regarded as a beacon of light for black African scholars barred from universities reserved for whites during apartheid, and trained several leaders and influential nationalists across sub-saharan Africa.

Mandela said in his autobiography that Fort Hare was like “Oxford and Cambridge, Harvard and Yale, all rolled into one.”