Port Elizabeth - Nelson Mandela University (NMU) students blocked the entrances at the South and North Campus on Thursday, the second day of a protest mainly over funding and registration.
The students are angry that some of them have been barred from registering over non-payment of fees, even though the government has pledged free tertiary education for learners from poor households.
The NMU said lectures on Thursday were postponed until further notice, urging students and staff to continue with their work off campus.
University spokesperson Zandile Mbabela said the institution would enforce an existing interdict against protesting students disrupting activities on campus.
Mbabela said physical disruptions would not be tolerated and NMU had a duty to protect the rights of staff, students and all other stakeholders.
"The interdict is aimed at protecting the rights of all university stakeholders – those who wish to access the university to work and pursue their studies as well as those wishing to exercise their right to protest in accordance with the conditions stipulated," she said.
Mbabela said a working group had been established last year comprising university management and student leaders with the aim of pre-empting perennial start-of-the-year challenges and putting measures in place to mitigate them as far as possible.
She said regular meetings of the working group had been taking place, with the most recent held on Tuesday.
"No issues were raised at this meeting that students believed were not being dealt with, and there were no issues raised that could have resulted in an interruption of university operations and academic activities," said Mbabela, adding that it was therefore surprising that students would block campus entrances.