At least six universities were damaged last month, while radical protesters occupied Chinese and Polytechnic Universities and surrounding areas, blocking roads and attacking officers with petrol bombs, the South China Morning Post said in the report.
Police responded with thousands of rounds of tear gas.
The most intense violence was at PolyU, where police besieged hardline protesters trapped on the campus for nearly two weeks.
Classes at 11 public and privately funded universities, as well as most of the higher education institutions, were cancelled for the rest of term.
Bruce Lui Ping-kuen, a senior lecturer at Baptist University's department of journalism, said that it had booked function rooms at a four-star hotel for lectures and provided free buffets for students. But he said attendance was only about 50 per cent so far.
While he had uploaded teaching materials online for his courses, and met students in small groups over meals outside campus, he said internet-based learning was flawed.
Meanwhile, students at the Hong Kong Design Institute (HKDI) have started a petition demanding refunds over suspended classes.
At the University of Hong Kong (HKU), exams were conducted online and students asked to record a video that "clearly shows the face of the student taking the exam", as evidence they had not cheated.
The Chinese University said faculties had "started to adopt alternative modes of teaching and assessment".
Monday marked the six-month anniversary of the start of the protests on June 9, when an estimated 1 million people took to the streets to oppose the now-withdrawn extradition bill.
Hong Kong's anti-government protests have transformed from peaceful demonstrations into outbreaks of violence, notably in tourist, commercial and residential districts.
( With inputs from IANS )