Video report by ITV News Asia Correspondent Debi Edward
Students from mainland China have been helped to leave Hong Kong after college campuses because the latest battleground in the region's five-month spiral into chaos.
Marine police used a boat to help a group of mainland students leave the Chinese University of Hong Kong on Wednesday.
It is also thought students from Taiwan, Denmark and Norway have been moved or urged to leave their campuses.
Authorities announced that primary and secondary school classes would be suspended on Thursday as clashes turn increasingly violent.
The protests have taken on a strong anti-China position, with radical demonstrators trashing branches of mainland banks, offices of China’s official Xinhua News Agency and restaurant chains whose owners support the Beijing government.
Hong Kong is part of China but has its own legal system and greater freedoms than the mainland. The protesters say those freedoms are under threat from a city government that is beholden to Beijing.
China says the protesters are rioters who want to break away from Chinese rule.
For the third day in a row, protesters widely disrupted train services, blocked streets and rallied in the central business district. They hunkered down for possible clashes with police at university campuses.
The Technical University of Denmark urged 36 students in Hong Kong to return home, saying “some of our students have been forced to move from their dormitories because they were put on fire”.
Norwegian student Elina Neverdal Hjoennevaag told her country’s broadcaster NRK that students are being sent to a hotel, adding: “I don’t really know what is happening. I must pack.”
Mainland students have said in online posts that they are being targeted by protesters who have broken into their dormitories, spray-painted insults on walls and banged on their doors, the Beijing Evening News reported.
Many are taking advantage of a programme that offers a week of free accommodation in one of a dozen hotels and hostels in the neighbouring mainland city of Shenzhen, Chinese media reported.
The service was established in 2013 for recent graduates looking for jobs in the tech hub.
Taiwan arranged flight tickets for 126 of its students at Chinese University to fly home on Wednesday night, public broadcaster RTHK reported.
Many subway and rail stations were closed after protesters threw debris on tracks and vandalised carriages. University classes remained suspended.
Hong Kong Baptist University told students that instruction and exams would be conducted online for the two remaining weeks of the semester, with arrangements for students who have returned to the mainland to join in.
The Education Bureau suspended classes at primary and secondary schools for safety reasons. Describing the situation as outrageous, the bureau said students should stay at home “and must not participate in any unlawful activities”.
Many of the masked protesters are thought to be high school and university students. Of the more than 4,000 people arrested since the protests began, nearly 40% are students, police said.