Violent clashes happened in at least 13 districts in Hong Kong on Sunday and sparked a backlash against police, who were heavily criticized for their “abuse of power” and allegedly failing to care about people’s lives.

On Monday morning, residents in Kwai Fong avoided going to the local subway as they feared tear gas fired inside the station the day before may pose a health hazard.

Several young people wearing masks handed out facemasks to commuters and asked people to protect themselves.

The railway operator had installed large fans inside the station to help with ventilation. A statement issued on Monday morning said it was regrettable that officers had reportedly used rubber bullets inside the station, as it threatened the safety of staff and passengers. It said staff evacuated passengers when they saw smoke inside the station.

The company said it had relayed its concerns to the police, and it condemns any form of violence.

Young people give out masks to commuters outside Kwai Fong subway station. Photo: RTHK

Ma Chung-Yee, president of Hong Kong Public Doctors’ Association, said firing tear gas inside an MTR station was like killing people in an indoor environment. He criticized the police as reckless and said they neglected thinking about people’s lives, Apple Daily reported.

‘Darkest weekend’

In their latest media briefing, anti-extradition protesters said on Monday that Hong Kong was on the verge of a humanitarian crisis – the people of Hong Kong just experienced the darkest weekend in the city’s modern history. And they observed a moment of silence to show sympathy to colleagues injured in the violence.

Activists also accused police of taking part in illegal acts during protests and framing demonstrators – and not just on Sunday.

“We have reasons to suspect that the police might have used undercover officers in many previous protests to start violent conflicts and participate in the illegal acts, such as the manufacture and use of gasoline bombs, arson, the attacks on police stations with bricks and the possession of highly offensive weapons, and then framed the protesters for committing these crimes,” spokeswoman Catrina Ko said.

They referred to an incident in Causeway Bay when a group of men dressed exactly like the protesters helped police to subdue people who were blocking Hennessy Road.

At a police press conference on Monday, Chris Tang Ping-keung, deputy commissioner of operations, admitted they did use undercover officers but refused to disclose whether they dressed like the protesters.

“The police will ‘decoy’ as any kind of people,” Tang said many times. He refused to say how many officers were doing undercover work in disguise and when they started to put police among the protesters after the fight against the extradition bill started in June.

Tang said they used undercover police to collect intelligence as they had identified around 15 “core” radical protesters, who they say carry dangerous weapons and have sparked attacks during the protests.

Asked if undercover police pretending to be protesters had been involved in violent acts that police accused the protesters of doing over the past two months – to frame protesters, Tang insisted that police would not do anything illegal or to provoke attacks.

Meanwhile, police also admitted that some of the tear gas they used in clearance operations had ‘expired’ – passed its use-by date – but they did not disclose what amount.

A policeman dressed like a protester helps police arrest a man in Causeway Bay. Photo: Screen-grab from TVB