A few dozen people remained trapped inside Hong Kong Polytechnic University (Poly U) on Wednesday, as lunchtime protests continued on the city's streets and China hit out at the passage of the Hong Kong Human Rights and Democracy Act by the Senate.
Poly U president Teng Jin-guang said that around 100 protesters are still on campus, 20 of whom are students there after a small number left to submit to arrest, citing deteriorating conditions inside.
"The campus is in a chaotic condition with dangerous chemicals," Teng told reporters. "Hygiene conditions are also deteriorating," he said.
"We believe that these conditions pose a significant risk to the people in the campus."
Five people were arrested after two protesters tried to escape via a sewer on Wednesday, as worried parents waited outside for news of their kids, government broadcast RTHK reported.
Police have pledged not to take under-18s into custody if they leave, while any adults will be arrested immediately on suspicion of "rioting," regardless of their role in the protests.
The United Nations expressed "deepening concern" over the situation in Hong Kong, which has been gripped by pro-democracy protests since June.
The U.N. Human Rights Office said it opposed violence by both protesters and police, and appealed to the administration of chief executive Carrie Lam "to do all they can to de escalate the situation, to address the humanitarian situation of those inside which is clearly deteriorating, and facilitate a peaceful resolution."
"At this juncture, we are deeply concerned at the risk of further escalation of violence in Hong Kong," the office said in a statement.
"Accountability for violence is also key – both in the case of individuals who have broken the law and committed acts of violence, but also in the case of allegations of excessive use of force by the police," it said, offering assistance in resolving the crisis through dialogue.
China slams rights bill
Hundreds of protesters blocked traffic in three districts at lunchtime on Wednesday using traffic barriers, cones and other items, chanting slogans calling on Lam to meet all five demands of the protest movement.
Around 200 masked protesters took to the streets in Kwun Tong, singing the anthem of the protest movement "Glory to Hong Kong," and chanting "Free Hong Kong! Revolution now!"
In Beijing, officials hit out at the passage of the Hong Kong Human Rights and Democracy Act by the U.S. Senate on Tuesday, saying it interferes in China's internal affairs.
"The bill disregards the facts, confuses right and wrong, violates the truth, plays with double standards, openly intervenes in Hong Kong affairs, interferes in China's internal affairs, and seriously violates the norms of international law and international relations," the foreign ministry said in a statement on its website. "China strongly condemns and resolutely opposes it."
"This bad behavior of the United States doesn't only harm China’s interests, but also undermines key interests of the United States in Hong Kong," the statement said.
"The Chinese central government will continue to firmly support the Hong Kong government and ... police in enforcing the law," it said.
Chinese scholar Zhang Yongqiang said the Chinese government is trying to whip up domestic nationalism in the face of the ongoing protests in Hong Kong.
"The main purpose of this condemnation is to brainwash people in this country," Zhang said. "The [ruling] Chinese Communist Party isn't currently in control of the situation in Hong Kong ... so it is looking for a scapegoat."
"They have found it in the United States, and the concrete evidence is the Hong Kong Human Rights and Democracy Act," he said.
A resident of the southwestern province of Sichuan surnamed He said state media are only reporting the Hong Kong protests in a selective manner, trying to stake out the moral high ground and keep the public on the side of the authorities.
"People with a conscience dare not speak out, and the rest of are being misled by mainland Chinese media," He said. "They are saying that there are pro-independence forces in Hong Kong who are trying to break up the motherland and destroy it, supported by Western hostile forces."
Arbitrary use of force
The Act will require Washington to enforce sanctions against any mainland or Hong Kong officials who carry out human rights abuses, and to carry out an annual review of the separate trading status accorded to the city based on Beijing's promises of non-interference there.
U.S. lawmakers have also approved a ban on the sale of tear gas, rubber bullets and other equipment to Hong Kong.
Chinese University of Hong Kong China expert Willy Lam said the bill won't necessarily be signed into law by U.S. President Donald Trump, however.
"It's hard to say whether Trump will sign it because he wants to make progress in trade negotiations with China," Lam said. "If he signs it, China will be angry and the trade agreement could be delayed."
The Hong Kong government said the bill was "unnecessary and unwarranted," and that the rights and freedoms of Hong Kong people were fully protected.
But the Bar Human Rights Committee of England and Wales (BHRC) said the Hong Kong authorities have sought to disproportionately limit and prevent legitimate and non-violent protest and assembly.
In a letter to Lam, the Committee said earlier calls for the police to refrain from disproportionate and deadly force had gone unheeded.
"The situation has now escalated to a very dangerous level," the letter said. "We recognize that a minority of the protesters have had recourse themselves to violence and we condemn any violence deployed on all sides."
But it cited credible media and social media reports that have shown "a reckless and arbitrary widespread use of force by the police, including arrests and use of force against journalists documenting the protests and first-aiders treating injured people."
"We are also concerned that tactics already being deployed including the firing of projectiles and teargas into confined areas, which represent a grave and disproportionate danger to life," it said, calling for an independent investigation into reports of police violence.
Reported by Wong Lok-to for RFA's Cantonese Service, and by Qiao Long for the Mandarin Service. Translated and edited by Luisetta Mudie.