Violence at the University of KwaZulu-Natal (UKZN) has escalated as four students were arrested during the protests, the police said on Wednesday."One student's vehicle was set alight by the protesters. The situation is stable. Police deployments remain in place for now," said police spokesperson Brigadier Jay Naicker.The arrests come as the police and campus security engaged in clashes on both the Howard and Westville campuses since the early hours of Wednesday.Naicker said Westville campus security had spotted around 600 students approaching the security officers' building at about 01:00.They were allegedly armed with petrol bombs and stones, forcing security guards to flee the scene. Upon their return, the security officers found the building had been set alight.Naicker said they then contacted the police who deployed public order policing units and the fire department.He added at about 07:00, around 1 000 students gathered at the Howard campus and allegedly forced other students to join them.Naicker said the large group moved to Princess Alice Street and set rubbish bins alight.Registration at the campus has since been suspended.READ: Tensions rise at UKZN as building set alight while hundreds of students protestEarlier, university spokesperson Ashton Bodrick denounced the protests as criminal behaviour, saying security staff and the police had worked tirelessly to safeguard the university community.He called the violence a "grave act of arson".Bodrick said while the university respected the students' rights to protest, there was no excuse for any act of violence and damage to valuable university resources and property.He added incidents of assault, destruction of property and arson were being investigated by the university's risk management services and police.The protests are part of a national drive by students to scrap historical debt so they can register for the academic year. The Unisa campus in Durban has also been affected, with registration coming to a halt since Monday.