Stranded passengers are seen at Hong Kong International Airport in Hong Kong, south China, Aug. 12, 2019. (Xinhua/Lui Siu Wai)

Such brutal and shameful acts are a flagrant violation of basic human rights, overstepping the bottom line of a civilized society.

HONG KONG, Aug. 14 (Xinhua) -- Violent protesters staged a shameful episode of sheer violence and brutality in full public view and broadcast on live television at the Hong Kong International Airport on Tuesday.

At about 8 p.m., a group of protesters detained a traveler they claimed to be an undercover police officer from the Chinese mainland.

In lynch mob-style assaults, they repeatedly kicked and punched the man, tied his's wrists together and pulled his identity documents from his wallet.

For nearly four hours, dozens of radical protestors attacked the man before he passed out. They even obstructed an ambulance crew from taking him to hospital.

Later, the protesters besieged and assaulted another man they claimed to be a fake reporter masquerading as a protester. Again, they beat him, tied his wrists together and continued assaulting him even as he was being taken away by paramedics on a stretcher.

Chinese newspaper the Global Times has confirmed the man is one of its reporters.

During an unpermitted rally at the airport terminal earlier in the day, they cursed and assaulted passengers and prevented them from departing, paralyzing for the second day the operations of the busy airport.

Such brutal and shameful acts are a flagrant violation of basic human rights, overstepping the bottom line of a civilized society.

The radicals' violent attacks on innocent citizens are tantamount to an act of terrorism that should be condemned in the strongest terms possible.

Their illegal detainment and brutal beating of a journalist is also an insult to the global press community and a serious violation of the freedom of the press.

On Wednesday, some protesters attempted to gloss over their atrocities by putting up half-hearted "sorry" signs, using soft language such as "imperfect decisions."

It is naive and absurd to think one can act with impunity. The only way for them to atone for their brutalities is to face the punishment by law.

Undoubtedly, the episode at the airport will be remembered in history as a stigma of Hong Kong.