Port Elizabeth – Two Nelson Mandela Metropolitan University (NMMU) students have been arrested following a clash with police in the early hours of Tuesday morning.It was not immediately clear what they were charged with. Police clear the main road to the NMMU campus. (Derrick Spies/News24) The university was expected to resume classes on Tuesday after it had been closed for four weeks. However, at around 05:30 a group of about 500 students blocked the main entrance – wearing balaclavas and wielding rocks. They used their residence mattresses to block the entrance.Thirty minutes later police arrived on the scene and advised the students to disperse. They told the students that if they did not disperse they would be detained for up to 24 hours because there was a court interdict in place which prohibited students from gathering and protesting.Police gave students three warnings before moving in. Students retaliated by launching a hail of rocks at them, which led to police moving in with a water cannon. Continuous battlesA clash between the two parties then broke out. Police used stun grenades and rubber bullets to try and disperse the students, who had begun running in different directions.Some sought refuge in a private residence near the university's north campus, but continued to throw rocks at the police, who again responded with teargas and stun grenades.By 07:00, police had cleared the main roads leading to the university and some students and staff could be seen making their way to the campus.The large group had broken up into smaller groups which engaged isolated yet continuous battles with the police.On Monday, four leaders of the NMMU's #FeesMustFall movement were arrested on the main campus.According to students, who did not want to be named for fear of reprisals, the four were part of a #FeesMustFall strategy meeting in the Embizweni building on south campus on Monday afternoon.Unsuccessful mediationNational police spokesperson Brigadier Sally de Beer confirmed the arrests at the time.She said the arrests took place at the university around 14:30 in terms of the Regulations of Gatherings Act.They were expected to appear in court on Tuesday.Last week Friday, the university's council met and agreed that the university must reopen. Following the council decision, the university obtained a court order for the institution to resume classes and take action against protesting students if necessary.The council decision came after a mediation process between various stakeholders including NMMU management, the NMMU #FeesMustFall movement and the Concerned Association of Parents and Others for Tertiary Education at Universities (Captu) broke down on Thursday.And while many students and lecturers have welcomed the announcement, the NMMU #FeesMustFall movement has accused the university of acting in bad faith and has vowed that the institution will remain closed.