According to police spokesperson Lt-Col Andrè Traut, the incident happened at about 9.30pm on Saturday.
Moholola said Mbatha's family had been informed and the university had offered them its full support.
The affected students had also been provided with counselling.
This is the second time the university has been rocked by the death of a student in recent weeks.
The murder of 19-year-old Uyinene Mrwetyana at a post office shocked the country.
Mrwetyana was murdered on August 24 and then disposed of in a hole next to a railway track in Khayelitsha, Cape Town.
The Sunday Times reported earlier this month that Mrwetyana's “killer” was on a list of 300 Post Office employees flagged by the State Security Agency in June 2018.
Former Cape Town councillor Jacques Webber said in a post on Facebook that he had received numerous messages about events at the beach on Saturday night.
“From what I am told, last night saw [thousands] of students descend on to the beach after matric farewell events. I was contacted when the first fight broke out and informed Law Enforcement Services who were already responding to the beach from various locations,” Webber said in his post.
* Warning — explicit language in tweets below.