Many Chinese mainland students at universities in Hong Kong have "fled" to neighboring Shenzhen or returned home, after rioters targeted major campuses amid the escalation of violent protests.

Rioters set fire to items at the Chinese University of Hong Kong subway station on Wednesday. (Photo: AP)

The students－some of them 19 and in their first year in the city－told China Daily on Wednesday that they feared the rioters' reckless assaults and bullying against people from the Chinese mainland.

During a forum between students and the president of the Hong Kong University of Science and Technology, a group of masked protesters attacked a PhD student, surnamed Zheng, from the Chinese mainland.

Similar violence was reported at the Chinese University of Hong Kong.

Since Monday, rioters have been vandalizing facilities and setting fires at major universities across the city. They brutally attacked people with different views in or outside the campus, with one victim being set on fire.

The violence escalated on Tuesday night. Rioters at CUHK hurled heavy objects and gasoline bombs from a footbridge outside the campus onto the Tolo Highway, a main thoroughfare in the New Territories, jeopardizing the safety of motorists and commuters.

The protesters clashed with the police, set fires and vandalized facilities in the nearby subway station. The violence forced the closure of the station and subsequently isolated the campus by cutting off transportation links for the students.

Various organizations from Hong Kong and neighboring Shenzhen helped the students, arranging buses and private cars to help transfer those affected across to the Chinese mainland. Some youth hostels in Shenzhen also offered free accommodation for the students.

Alice Lu, a master's program student at Hong Kong Baptist University, left the city through high-speed rail on Wednesday. Lu said her classes had been suspended for three days amid the chaos and she felt that her personal safety was threatened, especially with mainland students being attacked on campuses.

"I want to leave here as soon as possible," Lu said. "I feel like I'm living in a war zone … I'm very tired physically and mentally. What upsets me the most is why innocent people have to suffer all of this."

Celina Sang, a 19-year-old freshman at the City University of Hong Kong, told China Daily that she was frightened by what was happening on campus. She also heard people saying that some rioters had even entered university dormitories with lists of mainland students targeted.

Sang said her roommates had already left in panic. She herself left Hong Kong on a flight on Wednesday morning, without knowing when she would return to the city.

Sergey Lukanin, director of the Institute of Far East Studies at the Russian Academy of Sciences, said the violence has endangered the safety and stability of Hong Kong. "We can see some of the riots have funding support from overseas," he said.

"Many Hong Kong youngsters have been hoodwinked by people with ulterior motives, and those who want to ruin social stability will be punished eventually," he said.

Linda Yin-nor Tjia, assistant professor at the Department of Asian and International Studies at the City University of Hong Kong, said it was chaos at her campus. Tjia said classes have been suspended since Nov 11 and she herself opted to stay home as subway stations were vandalized.

Tjia said most of her graduate students are from the mainland.

"We have a group WeChat account and some of them told me that they went home (because of the escalating violence)."

Tjia said some of her students are also looking for temporary accommodation in Shenzhen so that it will be easy for them to return to Hong Kong once the situation calms down. She said another concern is the fact that a nearby mall was vandalized. The mall is connected to the Kowloon Tong MTR station and most students go through this mall to reach campus.

"My students don't want to be involved. They came to Hong Kong just to study," she said.

Iris Pang, economist for Greater China, ING, said: "The violence level in Hong Kong has escalated and more residents are reluctant to go out for shopping and dining. Some even choose to work from home.

"Tourists are also expected to stay away as they are even more cautious than the residents. This may hint at a worse quarterly GDP in the fourth quarter of 2019 compared to the third quarter."

Pang said that she can still go to work in the bank's office in the Central business district but only because she leaves her home before 7 am and takes a taxi.

"But I may not be able to leave (the office) at 6 pm. I must leave a lot earlier to avoid being stuck in traffic for three hours," she said.

Chandran Nair, founder and CEO of the Global Institute for Tomorrow, said the situation in Hong Kong now is very intense as everyone is pointing fingers at each other and leadership in all sectors is needed.

"The fact that people from the Chinese mainland are leaving is a real shame," said Nair, referring to media reports on how university students from the Chinese mainland decided to leave Hong Kong for safety concerns.

"We must find ways to live with others and respect them," said Nair, noting that people in Hong Kong should wake up to the reality that any violence and sense of resentfulness against others cannot be acceptable.

"The only way to bring the city back to peace is (that) everyone should take a moment to realize how close we are to something very bad happening," he said.

"History is clear. If you disagree with someone, the only way to find a way forward is to shake their hand and talk."

Terence Chong Tai-leung, associate professor at the Chinese University of Hong Kong's Lau Chor Tak Institute of Global Economics and Finance, said it is difficult for faculty staff living on campus to get food and dangerous for students who live in student halls if the situation escalates.

"The students need to know that what they do, including setting up barricades and fires on the roads, may put other people's lives in danger," said Chong. "They also need to know that what they do all have consequences… people should follow the rules."