Hong Kong: Frenzied mob violence on Tuesday against two men protesters suspected of being spies from mainland China marked the second day of pro-democracy demonstrations that have caused mass cancellations and disruptions in Hong Kong's busy airport. Calm eventually returned, with most of the protesters leaving the airport hours after officers armed with pepper spray and swinging batons tried to enter the terminal, fighting with demonstrators who barricaded entrances with luggage carts.
Riot police clashed briefly with the demonstrators, who said they planned to return to the airport early Wednesday.

More than 100 flights were cancelled on Tuesday, the fifth consecutive day that protesters occupied the airport. Airlines were still working through a backlog of more than 200 flights from Monday when the airport announced in the afternoon that check-in processes would once again be suspended. "Democracy is a good thing," said signs that appeared to be aimed at mainland Chinese and foreign travellers. Many signs also contained apologies for the disruption to travelers: "We stand here to obstruct, only for one single reason. We love and care for Hong Kong. We hope you will understand. Sorry."  The burst of violence included protesters beating up at least two men they suspected of being undercover agents and came the same day Hong Kong's pro-Beijing leader warned that the demonstrators had pushed events onto a "path of no return," highlighting the hardening positions on both sides.

Police have acknowledged using "decoy" officers, and the violence followed weekend sightings of men dressed like demonstrators in black and wearing face masks appearing to arrest protesters. In both instances, angry demonstrators pushed past people trying to hold them back and attacked the men, binding their wrists together and beating them to the ground. The two were eventually taken away by paramedics.

In one case, protesters detained a man they claimed to be an undercover police officer from mainland China, pulled his identity documents from his wallet and encouraged journalists to photograph them. None of them showed that he was a police officer, though protesters claimed to have found his name on an online list of police officers in southern Guangdong province. The Associated Press could not independently verify the man's identity.

Sally Tong, an 18-year-old protester, said they needed to hold him as evidence that mainland Chinese authorities are in Hong Kong to monitor the demonstrations. Tong said the man was dressed in black and wore a mask to look like one of them. "We want to keep him here and investigate," Tong said. Hours later, the protesters apprehended another man from mainland China. But they could not agree on who they believed he was: Some said he was a gangster, others said he was a fake reporter, and still others said he was masquerading as a protester.

As with the first man, some protesters tied his wrists together and poured water over his head, inciting laughter from some in the crowd. Airport security appeared unable to control the crowd. Hu Xijin, editor-in-chief of the Global Times, a nationalistic Chinese tabloid, said the man was one of his reporters. "Fu Guohao, reporter of GT website is being seized by demonstrators at HK airport," Hu wrote on his widely-followed Twitter account. "I affirm this man being tied in this video is the reporter himself. He has no other task except for reporting."

One protester used a US flag to beat Fu as he lay on the floor in a fetal position. Other protesters and first aid workers attempted to stop some who tried to trample the man, while pro-democracy lawmaker Kwok Ka-ki crouched beside him and tried to calm the attackers. After a heated argument, protesters eventually allowed ambulance workers to take the man away on a stretcher.

Hong Kong police said they arrested five people for unlawful assembly, assaulting police officers and possessing weapons. Officials said in a statement that some protesters detained, harassed and assaulted a traveller and a journalist, and obstructed ambulance workers from taking the two men to the hospital. They said other protesters attacked a police officer and snatched a baton from him. The airport disruptions escalated a summer of demonstrations aimed at what many Hong Kong residents see as an increasing erosion of the freedoms they were promised in 1997 when Communist Party-ruled mainland China took over what had been a British colony.

The central government in Beijing has ominously characterized the current protest movement as something approaching "terrorism" that poses an "existential threat" to citizens. The black-clad demonstrators have shown no sign of letting up on their campaign to force Hong Kong leader Carrie Lam's administration to respond to their demands, including that she step down and scrap proposed legislation under which some suspects could be sent to mainland China, where critics say they could face torture and unfair or politically charged trials.

Lam has rejected calls for dialogue, saying Tuesday the protesters were threatening to push their home into an "abyss." Meanwhile, paramilitary police were assembling across the border in the city of Shenzhen for exercises that some saw as a threat to increase force against the mostly young protesters who have turned out by the thousands in the past 10 weeks.