(Bloomberg) -- Tensions flared again in Hong Kong as an effort to form a peaceful human chain across the city culminated in police clashes that led to the firing of a weapon and the deployment of water cannons for the first time.

In the 12th weekend of disturbances, police and protesters were involved in several violent clashes in the western New Territories district of Tsuen Wan. On Saturday, Hong Kong Chief Executive Carrie Lam held a meeting with former officials and other prominent people to find a way out of the impasse that has rocked the former British colony.

Police arrested 36 people aged from 12 to 48 for alleged offenses including unlawful assembly, possession of weapons and assaulting police officers, according to a statement on the government website.

The return to violence followed large but peaceful protests the previous weekend. On Friday, protesters formed the human chain across the city, while a plan to again disrupt airport transportation services on Saturday wasn’t successful. Historic mass marches opposing legislation easing extraditions to China began peacefully in June, and have since widened into a broader movement against Beijing’s grip on the city.

Losing Patience

But in a sign that Beijing may be losing patience, China sent the strongest warning yet it’s thinking of using troops on Hong Kong’s streets.

“It’s not only China central government’s authority but also its responsibility to intervene when riots take place in Hong Kong,” the state-run Xinhua News Agency said Sunday in a commentary, drawing on comments by former top leader Deng Xiaoping saying Beijing has to act under such circumstances.

U.S. President Donald Trump said Aug. 13 that reports from the country’s intelligence agencies show the Chinese government is moving troops to its border with Hong Kong. A day earlier, Global Times, a Chinese tabloid run by the People’s Daily, reported that the Chinese People’s Armed Police were assembling in Shenzhen ahead of “apparent large-scale exercises,” where “numerous” armored personnel carriers, trucks and other vehicles of the paramilitary force were seen heading toward Hong Kong’s neighboring city.

In Sunday’s commentary, Xinhua said Hong Kong’s protests have turned into a “Color Revolution” aimed at overturning the Special Administrative Region’s constitutional institutions, a signal it was ready to take further action. Previously, Chinese officials had described the protests as having some characteristics of a “color revolution.”

‘Great Danger’

The Hong Kong police defended its officer’s decision on Sunday night to fire a shot in the sky, calling it “the best option” to disperse hundreds of protesters who were charging toward a fallen officer with metal poles and other weapons. Six officers had their guns drawn.

“Our officer’s life was in great danger,” Yolanda Yu, a police senior superintendent, said at a briefing early Monday morning, which started with video footage of black-clad protesters attacking the police. “The use of force was indeed necessary and reasonable -- it was to protect any person, including the officer himself, from death or serious bodily injury.”

About 15 officers were hurt in the clashes as Yu also stood by the move by an officer, who while holding his revolver, had kicked a protester. She called it a “natural reflex.”

Earlier in the day, the police used water cannons to clear barricades set up by protesters in Tsuen Wan, after firing multiple rounds of tear gas to try to disperse demonstrators who had occupied roads. Running battles continued into Sunday night in the area, before the streets were cleared at about 8:30 p.m., around the time of the gun shot.

Persistent Rain

People also began taking cover from the persistent rain and filled the stands and the pitch of the Kwai Chung sports stadium, the starting point for Sunday’s rally. The march from the stadium was granted late-night approval after organizers appealed an earlier objection by authorities.

“The rainy weather is good for the protesters but it’s bad for the police, who are wearing heavy gear. It also makes their tear gas ineffective,” said Gloria Mak, a 25-year-old assistant to a Japanese company.

The protest continued to disrupt the city’s essential services. Following flight cancellations with the shutdown of one of the world’s busiest airports almost two weeks ago, the operator of the city’s rail network suspended train services to stations near the planned Tsuen Wan march this weekend.

Biggest Challenge

MTR Corp. Operations Director Adi Lau Tin-shing said the current situation was the rail company’s biggest challenge in its 40 years of operation and that the station closures were an unavoidable decision taken on the grounds of safety.

Public property have also become a target. Police said “radical protesters” in Saturday’s clashes used electric saws to damage a number of smart lampposts, and hurled hard objects, bricks and petrol bombs at officers. They arrested 19 men and 10 women, aged between 17 and 52, for offenses including the possession of offensive weapons and assaulting police officers, the police said in a statement. Local TV news also showed protesters leaving after damaging toll booths at a cross-harbor tunnel.

In an attempt to ease tensions, Lam invited about 30 people to a meeting organized in Government House, including ex-transport chief Anthony Cheung and Cardinal John Tong, the former bishop of Hong Kong, RTHK reported. The city’s leader said the meeting was not a “dialogue platform” but a gathering to share ideas on how to build dialogue.

“I do not expect dialogue to easily resolve the deadlock, stop demonstrations, or to provide solutions to problems,” Lam said in a Facebook post. “But continuing to fight is not the way out.”

Revenue Impact

The fallout from the protest has also hit businesses. Cathay Pacific Airways Ltd., the city’s biggest carrier, said last week the demonstrations have a “much more significant impact” to revenue in August and onwards as business and leisure travel declined. Chief Executive Officer Rupert Hogg resigned days after the airport shutdown to take responsibility for the way the airline had responded to the events.

The carrier is also taking a tougher stance on employees, saying it wouldn’t tolerate workers supporting or taking part in illegal protests ahead of “planned activities” by the Hong Kong Confederation of Trade Unions on Aug. 26.

The Airport Authority Hong Kong obtained a High Court order to extend an interim injunction granted on Aug. 13 banning protesters from unlawfully obstructing access to the airport. That injunction covers Cathay City, “which is the operational hub for our global operations and as such includes facilities that are absolutely critical to our flight operations,” Cathay said in Saturday’s statement.

--With assistance from Justin Chin, Sheryl Tian Tong Lee and Venus Feng.

To contact the reporters on this story: Kari Lindberg in Hong Kong at klindberg13@bloomberg.net;Annie Lee in Hong Kong at olee42@bloomberg.net;Aaron Mc Nicholas in Hong Kong at amcnicholas2@bloomberg.net;Natalie Lung in Hong Kong at flung6@bloomberg.net

To contact the editors responsible for this story: Brendan Scott at bscott66@bloomberg.net, Linus Chua, James Ludden

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