HONG KONG -- Tensions rose in Hong Kong late Tuesday as hundreds of protesters began a nighttime vigil outside the city's parliament, just hours before lawmakers debate a divisive plan to allow extraditions to China.
The sudden appearance of around 2,000 predominantly young protesters after 11 p.m. (1500 GMT), some carrying tents and supplies, was met by a marked increase in police reinforcements, many of them equipped with riot gear.
The financial hub was rocked over the weekend by the largest protest march since the city's 1997 return to China, as vast crowds called on authorities to scrap the Beijing-backed plan.
Many are fearful the proposed law will tangle people in the mainland's opaque courts and hammer Hong Kong's reputation as an international business hub.
Organizers of the march said more than a million people took to the streets on Sunday.
But the record crowds have failed to sway chief executive Carrie Lam who has rejected calls to withdraw or delay the bill and warned opponents against committing "radical acts".
On Wednesday morning lawmakers will begin debating the bill in the city's legislature, which is dominated by Beijing loyalists. A final vote is expected on June 20.
Protest groups had called for a rally on Wednesday as legislators debate but many arrived hours earlier saying they planned to spend the night in a park next to the complex.
"I want to do something before our freedoms are taken away," Yu Wing-sum, 23, told AFP.
It was not clear whether police would allow the protest to continue.
At the end of Sunday's peaceful march officers fought running battles with small groups of hardline protesters who had made similar plans to spend the night.
Throughout Tuesday evening police flooded the area around the government offices, stopping and searching many young people. By midnight there had been no attempt to move the crowds on.
The extradition proposals have united a wide cross-section of society against the government.
Business owners have taken to social media using a hashtag that translates as "#612strike" -- the date of the proposed action -- to announce solidarity closures.
A large chunk are mom-and-pop style stores and small businesses that are an important part of the city's economy, but which often eschew the city's raucous street politics.
More than 100 businesses had declared plans to strike, ranging from coffee shops and restaurants to camera stores, toy shops, nail salons, yoga studios and even an adult entertainment store.
"Hong Kong was built by our various generations with hard work," wrote Meet Yoga studio on its Instagram account. "A Hong Kong without freedom -- how about we just wipe it off the map entirely and call it China?"
The city's major student unions said they would boycott classes to attend the rallies, while a string of other prominent unions in the transport, social work and teaching sectors either followed suit or encouraged members to attend.
Earlier Tuesday, Lam warned against strikes, a protest method that is not readily embraced in the business-centric city.
"I urge schools, parents, groups, corporations and unions to carefully consider, if they call for these radical acts, what good would it do for Hong Kong society and our youth?" local broadcaster RTHK quoted her as asking.
The proposed law would allow extraditions to any jurisdiction with which Hong Kong does not already have a treaty -- including mainland China.
Hong Kong's leaders say it is needed to plug loopholes and to stop the city being a sanctuary for fugitives, and that safeguards are in place to ensure that political critics of Beijing will not be targeted.
Many Hong Kongers have little faith in the government's assurances after years of heightened fears that a resurgent Beijing is trying to quash the city's unique freedoms and culture -- despite a 50-year agreement between Hong Kong's former colonial ruler, Britain, and China which means the city is guaranteed freedoms of speech and assembly unseen on the Chinese mainland.
Massive pro-democracy demonstrations in 2014 failed to win any concessions while protest leaders have been imprisoned or banned from politics.
On Tuesday, New Zealand's top court stopped a murder suspect from being extradited to Shanghai in a landmark ruling that gave a scathing assessment of China's courts.
The Court of Appeal noted a culture of torture, forced confessions and months-long interrogations without lawyers in China's judicial system while defense counsels were often persecuted.
Opposition to extradition unites a wide cross-section of Hong Kong, including lawyers and legal bodies, business figures and chambers of commerce, journalists, activists and religious leaders.
The pastor of a usually pro-government mega-church issued a statement saying he could not support the bill while the Catholic diocese urged Lam -- a devout Catholic -- to delay the bill.
Western governments have also voiced alarm.
The US this week warned the bill would put people at risk of "China's capricious judicial system".
China fired back Tuesday. A foreign ministry official called the comments "irresponsible and erroneous", adding that Beijing "resolutely opposes interference in Hong Kong affairs".
© Agence France-Presse