Dozens of people remained trapped inside the Hong Kong Polytechnic University (Poly U) on Tuesday as police said anyone left inside would be arrested and hospitals were flooded with hundreds of people injured during the standoff.
Riot police have laid siege to Poly U campus, blocking all exits and firing tear gas and water cannon at people trying to leave, while protesters inside have fired petrol bombs from makeshift catapults behind defensive barricades.
Police have also detained medical volunteers and reporters trying to leave campus, amid reports of a stampede caused by police attacks on a crowd of hundreds in nearby Yaumatei district.
Hong Kong chief executive Carrie Lam said some 600 people have left the Poly U campus since the siege began, 200 of whom were minors.
Lam said the minors had had their details taken down, while some 400 people were "immediately arrested, whether they came out peacefully on their own, surrendered themselves to the police, or they came out using various methods and were caught by the police during this operation."
"The latest assessment given to me is that perhaps there would be about a hundred or so people still on campus," she said, calling on those who remain to come out peacefully and submit to arrest.
Ambulance crews have been taking scores of injured people out of the university buildings since Monday night, while others have made daring bids for freedom by abseiling down from bridges and running along the tops of footbridges.
A group of some 20 voluntary first responders said they remain trapped after entering the campus to give medical assistance to those inside.
"We are angered and disappointed by the government and police force's neglect towards the legal rights of people in HK," the group said in a statement on Tuesday. "We were only there to provide medical rescue [but] the government and police are threatening to charge us for taking part in a riot and are trapping us inside the campus."
Trampling incident reported
The Hospital Authority said on Tuesday that emergency rooms across the city are currently treating around 80 casualties from Poly U, while 200 people have been transferred to different hospitals for treatment.
Meanwhile, the city's Fire Services Department says officers witnessed a heap of people lying in the road in Yaumatei on Monday night, confirming widespread social media reports of a crush and trampling incident in which around 30 people were taken to hospital, some with serious injuries.
"The incident followed serious clashes between police and anti-government protesters along Nathan Road, with police firing tear gas and other weapons to counter the petrol bombs being thrown at them," government broadcaster RTHK reported. "[Police] also confirmed that a flash grenade was used in the area," it said.
Social media reports accused police officers of driving a vehicle into a crowd of protesters, causing them to panic and trample each other.
Incoming police commissioner Chris Tang said the police have a responsibility to "maintain law and order."
"[There is a] massive scale of breaking of law in Hong Kong, and there’s a certain sector of society that also condones those illegal activities," Tang told reporters. He ruled out setting up an independent commission of inquiry to pursue complaints of police violence, one of the key demands of the protest movement.
Police have been the focus of widespread public anger after video footage showed them failing to protect protesters and passers-by from attacks by pro-China thugs in Yuen Long district on July 21. Several prominent pro-democracy figures have also suffered violent attacks, and the perpetrators have yet to be found.
Former Democratic Party chairman Albert Ho was attacked by two masked men on Tuesday night, suffering multiple injuries to his back and arms including a suspected fracture, he told journalists.
Ho said he was beaten by a "long, hard object" in an alleyway in Hong Kong Island's Tin Hau district, RTHK reported.
US 'gravely concerned'
The United States said it is "gravely concerned" the situation in Hong Kong, including the siege at Poly U and other universities last week.
"Violence by any side is unacceptable," Secretary of State Mike Pompeo told a regular news briefing in Washington. "Unrest and violence cannot be resolved by law enforcement efforts alone. The government must take clear steps to address public concerns."
Pompeo called on Lam to order an independent investigation into protest-related incidents, and called on the ruling Chinese Communist Party to "honor its promises" of the continuation of their traditional freedoms under Chinese rule.
Rights groups have warned that Hong Kong is now in a state of humanitarian crisis after police fired more than 10,000 rounds of tear gas in recent months, with around 20 percent of those fired into the Chinese University of Hong Kong (CUHK) campus during a single day last week.
Lam formally withdrew a planned amendment to the city's extradition laws last month, fulfilling the first of the protest movement's five demands.
But protesters say they will continue until there has also been an amnesty for thousands of people arrested, the withdrawal of the official term 'rioting' to describe the movement, an independent inquiry into police violence against protesters, and fully democratic elections to the Legislative Council and for the post of chief executive.
Government officials have repeatedly ruled out these measures, while calling at the same time for "dialogue" with protesters.
In recent weeks, calls have been growing for the current Hong Kong police force to be disbanded, particularly after widespread reports of the sexual abuse and torture of detainees at the hands of police.
Reported by Wong Lok-to, Lau Siu-fung, Tseng Lap-yin, Man Hoi-tsan and Sing Man for RFA's Cantonese Service, and by Qiao Long for the Mandarin Service. Translated and edited by Luisetta Mudie.