The protracted social unrest in Hong Kong is an attempt to overthrow the special administrative region government and turn the city into an "independent or semi-independent political entity", China's top diplomat in Hong Kong special administrative region said on Thursday.

Calling the attempt "no more than wishful thinking", Xie Feng, commissioner of the Ministry of Foreign Affairs of China in HKSAR appealed to the international community to not endorse any form of violence.

Addressing the opening ceremony of the International Forum on the Guangdong-Hong Kong-Macao Greater Bay Area, Xie labeled the street violence in Hong Kong as "virus which is even more deadly than SARS".

Protests against the now-withdrawn extradition bill have gripped the city for over four months. Masked, black-clad rioters have hurled petrol bombs at police and committed arson and vandalism to government buildings, metro stations and mainland-related stores and restaurants. The masked protesters also beat ordinary people bloody, solely because the latter voiced different opinions.

Official data showed that retail sales tumbled 23 percent year-on-year in August, the sharpest monthly drop on record. The city's other economic pillar, the tourism industry, recorded in August a 40 percent year-on-year decline in visitor arrivals. Hotel occupancy has fallen roughly 50 percent and even 80 percent in protest-hit areas.

Behind the violence, there is the "black hand" – the opposition in Hong Kong and foreign forces, who have been selectively blind and deaf to violence, and even told blatant lies to romanticize the unrest, Xie said.

Their true motive is "to mess up the city, overthrow the legitimate government, seize jurisdiction, and ultimately destroy "one country, two systems" by turning Hong Kong into an independent or semi-independent political entity," he said.

The street violence in Hong Kong has also found its way to the international arena. Protesters in Spain, the UK and Chile have imitated Hong Kong-style street violence.

Xie warned that should the Pandora's box of street violence be opened and rioters continue to "defy the law for the sake of justice" as they claim, human civilization as a whole would be plunged into calamity and no country would be immune.

He then called on the international community not to remain silent, stand idly by, or gloat at the unrest in Hong Kong, still less endorse the rioters.

Xie's remarks echoed what spokesman for the State Council's Hong Kong and Macao Affairs Office Yang Guang said in early October. Yang noted that the protests in Hong Kong showed signs of "color revolution".

On the same occasion, Hong Kong Chief Executive Carrie Lam Cheng Yuet-ngor said the city would hold fast to the "one country, two systems" principle as well as the rule of law to ride out the "unprecedented" political storm Hong Kong is experiencing.

Noting Hong Kong is facing unprecedented social problems, Somkid Jatusripitak, deputy prime minister of Thailand, said a similar situation occurred in his country before, resulting in Thailand missing out on development opportunities for several years.

"In these difficult circumstances, I believe that everyone with inner justice will see the efforts made by the Chief Executive (of Hong Kong) to alleviate the problem in a sensible manner and in a peaceful manner," said Somkid.