This article is more than 1 year old

This article is more than 1 year old

Rights groups and democracy activists have accused police in Hong Kong of using excessive force after teargas was fired into an enclosed subway station and officers posed as protesters before making arrests during an intense weekend of clashes.

“Clashes between protesters and police over the weekend escalated to another level especially on the police side,” said Man-Kei Tam, director of Amnesty International Hong Kong.

Tam cited video footage of police firing teargas into a subway station on Sunday night in Kwai Fong. It was not clear how many protesters were inside the station at the time, but it has been rare for officers to fire tear gas indoors. He also shared footage of police firing non-lethal projectiles at close range as protesters attempted to flee down a separate subway station escalator.

Quick guide What are the Hong Kong protests about? Show Hide Why are people protesting? The protests were triggered by a controversial bill that would have allowed extraditions to mainland China, where the Communist party controls the courts, but have since evolved into a broader pro-democracy movement. Public anger – fuelled by the aggressive tactics used by the police against demonstrators – has collided with years of frustration over worsening inequality and the cost of living in one of the world's most expensive, densely populated cities. The protest movement was given fresh impetus on 21 July when gangs of men attacked protesters and commuters at a mass transit station – while authorities seemingly did little to intervene. Underlying the movement is a push for full democracy in the city, whose leader is chosen by a committee dominated by a pro-Beijing establishment rather than by direct elections.

Protesters have vowed to keep their movement going until their core demands are met, such as the resignation of the city’s leader, Carrie Lam, an independent inquiry into police tactics, an amnesty for those arrested and a permanent withdrawal of the bill. Lam announced on 4 September that she was withdrawing the bill. Why were people so angry about the extradition bill? Beijing’s influence over Hong Kong has grown in recent years, as activists have been jailed and pro-democracy lawmakers disqualified from running or holding office. Independent booksellers have disappeared from the city, before reappearing in mainland China facing charges. Under the terms of the agreement by which the former British colony was returned to Chinese control in 1997, the semi-autonomous region was meant to maintain a “high degree of autonomy” through an independent judiciary, a free press and an open market economy, a framework known as “one country, two systems”. The extradition bill was seen as an attempt to undermine this and to give Beijing the ability to try pro-democracy activists under the judicial system of the mainland. How have the authorities responded? Beijing has issued increasingly shrill condemnations but has left it to the city's semi-autonomous government to deal with the situation. Meanwhile police have violently clashed directly with protesters, repeatedly firing teargas and rubber bullets. Beijing has ramped up its accusations that foreign countries are “fanning the fire” of unrest in the city. China’s top diplomat Yang Jiechi has ordered the US to “immediately stop interfering in Hong Kong affairs in any form”. Lily Kuo and Verna Yu in Hong Kong

Tam questioned the need for such force in both cases as protesters appeared to be showing “no aggression” towards officers. “These are all very ugly things,” he said.

Pro-democracy street protests in Hong Kong stretched into their 10th week on Monday with no sign of either side backing down. The police have also reported injuries among their ranks, including eye irritation from laser pointers and burns from a petrol bomb.

Civil Rights Observer, a local rights group that sends observers to protests, said it had “very serious concerns” about police violence and had seen “very clear evidence to show the police are violating their guidelines”, according to its spokesman Icarus Wong.

He said the group was particularly concerned by the use of undercover officers for the first time, who later turned on protesters on Sunday night. He said it was unclear if they may have acted as agitators before making mass arrests.

Facebook Twitter Pinterest A protester throws back a tear gas round as thousands marched on police headquarters in their fight against the Hong Kong government. Photograph: Aidan Marzo/SOPA Images/Rex/Shutterstock

During the weekend protests, the website Hong Kong Free Press showed footage of one arrest that appeared to include officers dressing as protesters who injured a demonstrator pressed to the ground. The young man, who said his name was Chow Ka-lok and asked for a lawyer, was left with bleeding head wounds and a broken tooth.

Outrage against police violence quickly spread online, where a sit-in at Hong Kong International airport was quickly organised over social media for Monday afternoon.

Many residents also shared videos and photos of police violence on Twitter, in some cases under hashtags such as #AbolishHKPF and #HKPoliceState, as well as in Telegram protest groups. One commonly shared photo included an image of a female protester hit by a police projectile and bleeding profusely from her eye.

“Let us [admit] HK is a police state. Riot police push down peaceful protestor on the escalator of railway station,” the democracy activist Joshua Wong tweeted.

“Hong Kong police repeatedly shooting rubber bullets from 1m distance at protesters who are leaving and entering Taikoo MTR station. How is this acceptable behavior?????” Denise Ho, a cantonese pop star turned activist tweeted.

Facebook Twitter Pinterest A woman receives an eye wash from volunteer medics after she was affected by tear gas during a protest in the Tsim Sha Tsui area of Hong Kong’s Kowloon district. Photograph: Anthony Wallace/AFP/Getty Images

Over the weekend journalists were also attacked by mobs of residents believed to be pro-China supporters in one district on Hong Kong island.

“Violence against journalists, whether it comes from the police or pro-Beijing mobs, has become systematic and clearly aims to discourage the media from covering the protests in Hong Kong,” said Cédric Alviani, the head of the Reporters Without Borders East Asia bureau, who called for an independent investigation into protest brutality.

Facebook Twitter Pinterest Anti-extradition bill protesters attend a mass demonstration after a woman was shot in the eye during a protest at Hong Kong International airport. Photograph: Tyrone Siu/Reuters

On Monday legislators and journalists were also invited to witness a display of police water cannons, which Amnesty warned last week could lead to serious injuries if misused within Hong Kong’s confined spaces.

Protests in Hong Kong began in early June against a legislative bill that would have allowed for residents to stand trial in mainland China on criminal charges.

While Hong Kong returned to Chinese rule in 1997, it was promised semi-autonomy for 50 years including a separate legal system. Many protesters feared the bill, now suspended, would have led to the decline of civil and political rights in the Asian financial hub.