'Something extraordinarily bad is about to happen': Huge Chinese military build-up filmed on Hong Kong border as all flights cancelled

Large numbers of Chinese paramilitary forces have been filmed assembling just 30km from Hong Kong in the city of Shenzhen, as the UN warned Beijing to exercise restraint in its response to growing unrest in the territory.

Hong Kong’s pro-Beijing leader Carrie Lam said on Tuesday that the city had been placed on a “path of no return” after 10 weeks of increasingly disruptive protests.

Flights at the international airport in Hong Kong were cancelled for a second day, as thousands of demonstrators gathered in the departure hall at the main terminal despite the implementation of increased security measures designed to keep them out.

Chinese state media described the buildup of armed police units, shown in videos gathering at an arena called the Shenzhen Bay Sports Centre, as preparations for “apparent large-scale exercises”. Alexandre Krauss, a policy advisor for the EU's Committee on Foreign Affairs, called the videos a sign that "something extraordinarily bad is about to happen".

Similar exercises on 6 August featured up to 12,000 troops, according to the Chinese state-run Global Times newspaper, and featured armoured personnel carriers, helicopters and amphibious vehicles.

The newspaper described the People’s Armed Police forces as being mandated by Chinese law for “dealing with rebellions, riots, serious violent and illegal incidents, terrorist attacks and other social security incidents”.

It is a further sign of Beijing’s waning patience with the unrest in Hong Kong, after the Chinese government said on Monday that the protest movement in the city had begun to show “sprouts of terrorism”.

While China defines terrorism loosely, it has previously used the term to describe non-violent opposition movements in minority regions such as Tibet and Xinjiang, justifying greater uses of force and the suspension of legal rights for detainees.

Speaking on BBC radio, Britain’s last governor of the city before the 1997 handover said it would be “a catastrophe for China and of course for Hong Kong” if there was a military intervention.

Chris Patten said it was counter productive of China to warn of “other methods” if the protests did not stop. “Since President Xi has been in office, there’s been a crackdown on dissent and dissidents everywhere, the party has been in control of everything,” he said.

“I very much hope that even after 10 weeks of this going on, the government and President Xi [Jinping] will see the sense in establishing a way of actually bringing people together,” Lord Patten said.

Steve Tsang, director of the China Institute at Soas University of London, said that despite repeated shows of force “we are still some distance from [Chinese] security forces being deployed in Hong Kong”.

“But it is much closer today than a month ago,” he added, when protesters targeted the main central government headquarters in Hong Kong and a Chinese flag was defaced.

Mr Tsang said the shift in China’s perception of the protests, rather than its troop movements, was the critical issue. “Beijing now sees events in Hong Kong as a ‘colour revolution’… part of an American-led global conspiracy which aims ultimately at regime change in China,” he said. “This is totally intolerable to Xi Jinping.”

In a statement, the UN High Commissioner for Human Rights Michelle Bachelet said that by conflating the Hong Kong protests with “terrorism”, China risked inflaming the situation.

She urged the authorities to exercise restraint and to investigate evidence of uses of excessive force by police – one of the protesters’ key demands.

“Officials can be seen firing tear gas canisters into crowded, enclosed areas and directly at individual protesters on multiple occasions, creating a considerable risk of death or serious injury,” Ms Bachelet said, referring to videos of recent clashes in the city.

Ms Lam, however, reiterated her support for the police and their tactics, saying they have had to make on-the-spot decisions under difficult circumstances, using “the lowest level of force”.

During angry exchanges in which reporters repeatedly shouted over her, Ms Lam said dialogue would only resume “after the violence has been stopped, and the chaotic situation that we are seeing… subside[s]”.

And she again dismissed calls for her resignation, saying that: “I, as the chief executive, will be responsible to rebuild Hong Kong’s economy ... to help Hong Kong to move on.”