Thousands of anti-extradition protesters converged on Hong Kong's international airport on Monday, prompting the authorities to cancel all remaining flights from the city.
"Airport operations at Hong Kong International Airport have been seriously disrupted, all flights have been cancelled," the Airport Authority said in an emergency announcement on its website.
"All passengers are advised to leave the terminal buildings as soon as possible."
The move came after thousands of protesters wearing black gathered in the departure hall of the airport at Chek Lap Kok on the fourth day of a sit-in aimed at getting the protesters' demands across to the international community.
Chanting "An eye for an eye," and "Shame on the crooked cops!" many protesters said they were angry at the shooting of a woman in the eye with a bean bag bullet.
Government broadcaster RTHK said the woman had undergone emergency surgery after her right eye was ruptured and some of her facial bones fractured.
Photos were later circulated online with what looked like a bean bag round lodged in the goggles said to be found next to her, it said.
Others hit out at the use of tear gas inside Kwai Fong MTR station, as police were pictured firing on protesters who were already leaving, in an enclosed space.
Live target practice
Icarus Wong, a member of the Civil Rights Observer group, said certain police officers seemed to see protesters as live targets.
"The police had great strength in numbers [on Sunday], so they could have brought the situation under control and made arrests without using weapons," Wong said.
"Certain police officers were firing pepper spray at protesters, as if they were using it for live target practice, rather than as a means to control the crowd," he said.
Amnesty International Hong Kong also hit out at police violence in a statement issued on Monday.
"Firing at retreating protesters in confined areas where they had little time to leave goes against the purported objective of dispersing a crowd," the group said.
Police fired multiple rounds of tear gas, and pepper ball projectiles were fired within a short range inside a train station in Kwai Fong ... against protesters, sometimes aiming at their heads and upper bodies, the rights group said in a statement.
It said tear gas, rubber bullets, and pepper ball projectiles can cause serious injury and are potentially lethal.
Heavy-handed policing
The group said tear gas should never be used in confined spaces or where exits are blocked or restricted, nor should canisters be fired directly at anyone and should not be fired at all when visibility is poor.
“The Hong Kong police have once again demonstrated how not to police a protest," Amnesty International Hong Kong director Man-kei Tam said.
“Violence directed at police does not give officers a green light to operate outside of international policing standards.”
“Any heavy-handed policing approach will only increase tension and provoke hostility, leading to the overall escalation of the situation.”
The group called on international governments to suspend transfers of crowd control equipment to Hong Kong until a full and independent investigation is carried out, and adequate safeguards are put in place.
And a group of MTR railway staff issued a statement slamming police actions against protesters in and around railway stations in recent weeks.
"We condemn the behavior of the police ... [which] endangers the life of not only frontline staff, but also passengers' safety," the statement, issued via the MTR Secrets page on Facebook, said. "The Hong Kong Police should desist from similar operations."
'Signs of terrorism'
In Beijing, the Hong Kong and Macau Affairs Office said the anti-extradition movement in Hong Kong is starting to show “signs of terrorism," once more saying it supports the city's police force.
"In the past few days, radical protesters in Hong Kong have repeatedly attacked police officers with extremely dangerous weapons," spokesman Yang Guang told reporters. "Their actions have constituted serious violent crimes and have now begun to show signs of terrorism."
"They also pose a serious threat to the prosperity and stability of Hong Kong," Yang said, adding that the priority for the administration of chief executive Carrie Lam must be to end the violence.
Media reports have indicated a build-up of People's Armed Police forces across the border in Shenzhen, although analysts say an armed intervention in Hong Kong is unlikely ahead of the ruling Chinese Communist Party's Oct. 1 celebrations of the 70th anniversary of the founding of the People's Republic.
A recent video showed a total of 12,000 police officers drilling in an anti-riot scenario against protesters wearing similar clothes to those in Hong Kong, the Global Times newspaper reported on Aug. 6.
Police work in disguise
Protesters told a news conference on Monday that Hong Kong is on the verge of a humanitarian crisis, accusing police of dressing up as protesters to initiate violent conflicts including making petrol bombs.
"We have reason to suspect that the police might have used undercovers in many previous protests to start violent conflicts and participate in illegal acts like the manufacture and use of gasoline bombs, setting fires, attacks on police stations with bricks, and the possession of highly offensive weapons, and then framed protesters for committing these crimes," anti-extradition movement spokeswoman Catrina Ko told reporters.
"The protesters are not destroying Hong Kong. They are rescuing it from an unimaginably grim future," Ko said. "We Hongkongers should not yield."
The police admitted on Monday to disguising themselves as protesters and helping to make arrests in Causeway Bay on Sunday.
Deputy police commissioner Chris Tang said the force had engaged in some "intelligence-led" operations targeting protesters allegedly carrying offensive weapons.
"We have to use a range of methods to deal with this, but our officers definitely didn't incite any incidents or break the law in any way," Tang told a news conference, but declined to give details, citing operational security.
As the Civil Human Rights Front called for another peaceful mass rally next weekend, student unions at 11 higher education institutions called on Monday for an indefinite strike in the city, in protest at police violence.
The groups called on Hong Kong people to immediately stop going to work or classes, and shut their businesses down, as police were "totally out of control" and had been using excessive force on protesters, reporters and bystanders since the protest escalated in early June.
"Democracy and also the freedom in Hong Kong is more important than rents and salaries," Chinese University of Hong Kong student union president Jacky So said.
"If there isn't any more freedom in Hong Kong, then actually we are nothing," he said.
Support from US, Taiwan
In the United States, Senate Majority Leader Mitch McConnell tweeted support for the protesters and called for restraint from China.
"The people of Hong Kong are bravely standing up to the Chinese Communist Party as Beijing tries to encroach on their autonomy and freedom. Any violent crackdown would be completely unacceptable. As I have said on the Senate floor: The world is watching," McConnell posted with his majority leader profile.
In democratic Taiwan, president Tsai Ing-wen said the violent crackdown wasn't an adequate response to the anti-extradition movement.
"The serious clashes with police in Hong Kong yesterday have given everyone who supports freedom and democracy around the world cause for concern," Tsai said in a statement. "Violent suppression isn't going to solve the problem."
"The Hong Kong authorities should face up to and take seriously the demands of citizens for freedom and democracy, so as restore peace and public order," she said.
Tsai, who is running for re-election in 2020, said many are worried that what is happening in Hong Kong could happen in Taiwan, as the Chinese Communist Party has refused to renounce the use of force to annex the country, which it has never controlled, and which is a sovereign state flying the flag of the 1911 Republic of China.
"I assure you that as long as I am in my post, you don't have to worry about Taiwan turning into another Hong Kong," Tsai said.
The anti-extradition protests are calling on Carrie Lam to formally withdraw planned amendments to extradition laws that would allow alleged criminal suspects to be sent to face trial in mainland courts, to release all protesters without charge, and to stop describing the protests as riots or protesters as rioters.
They also want the government to set up an independent public inquiry into police use of tear gas, batons, rubber and textile bullets, and batons to attack crowds of largely peaceful demonstrators, and their failure to prevent bloody attacks by triad-linked thugs on protesting crowds in Yuen Long and North Point.
And they want Lam to formally dissolve the Legislative Council (LegCo) and implement political reforms leading to fully democratic elections with public nominations both to the legislature and for the city's chief executive.
But Lam has refused all along to countenance such concessions, preferring to focus on the economic costs of the protest movement without addressing the political crisis that sparked it.
Reported by Qiao Long and Gao Feng for RFA's Mandarin Service, and by Wen Yuqing for the Cantonese Service. Translated and edited by Luisetta Mudie.