HONG KONG — Hong Kong protesters began the new year the way they’d spent much of the old one: in the streets.
Nearly a month of relative quiet abruptly ended on Wednesday with the sounds of protesters’ chants and police officers’ tear-gas rifles.
A peaceful New Year’s Day march descended within a few hours into violent clashes. Riot officers deployed water cannons and pepper spray. Protesters built barricades out of umbrellas and paving stones, and vandalized at least two branches of a leading bank in the city, HSBC.
“The government is not willing to back down at this moment,” said Grace Ng, 30, a public relations professional who has attended half a dozen marches since the protests began. “I want the government to compromise, but I think there isn’t enough international attention at the moment to make them bow down to the people.”
As the movement enters the new year, its momentum is in question. It remains to be seen if the protesters have the stamina, public support or inclination to continue to battle the government, which has repeatedly said it will not concede to their demands for greater democracy.
It is also unclear how long the city itself can endure a movement that has already resulted in 6,000 arrests and an economic recession.
“I believe a lot of us have no idea what to do next,” said Jessica Man, 19, a university student. “I don’t know what we could do to keep ourselves going.”
At the heart of the protests is concern about the erosion of civil liberties in Hong Kong, a former colony that was promised a unique set of freedoms when Britain handed it back to China in 1997. Those fears have been compounded by economic issues, including soaring housing prices, income inequality and a dearth of high-paying jobs.
In November, Hong Kong expressed its support for the protests at the polls, overwhelmingly electing pro-democracy politicians to neighborhood offices. It was a stinging rebuke to Communist Party officials in China, and it ushered in the longest period of relative calm since the protests began.
Wednesday’s march was the second large-scale demonstration that the police had authorized since the election, and tens of thousands took to the streets, if not more. But hours after it began, the police rescinded their permission, citing an outbreak of violence and vandalism. Large numbers of people were still waiting to march at the event’s staging area when the police made the announcement.
The Civil Human Rights Front, which organized the march, called the police’s decision “absurd” and accused them of escalating tensions by firing tear gas at a crowd. It said in a statement that unless protesters’ demands were met, “Hong Kongers shall not back down, and peace shall not resume with ongoing police brutality.”
By nightfall, familiar scenes were playing out on the streets, as protesters built barricades, lit fires and squared off against the riot police. Several dozen people were rounded up by the police in the Causeway Bay area; witnesses said some of them had been bystanders. A pro-democracy lawmaker, Ted Hui, was pepper-sprayed directly in the face by a police officer, after the officer tore off Mr. Hui’s protective goggles.
Ng Lok-Chun, a senior police superintendent, later said that about 400 people had been arrested, and that charges included taking part in an illegal assembly and possessing weapons. He said the police had revoked the march’s permission because some participants had “hijacked the procession” and “threw a petrol bomb at an officer.”
“The police were reluctant to terminate the march,” he said.
The protests began in June over legislation, long since scrapped, that would have allowed extraditions to mainland China, where the courts are opaque and subordinate to the Communist Party. The protesters have since expanded their demands to include a broad range of grievances, including greater democracy and an investigation of alleged police brutality.
The march on Wednesday stretched the movement’s scope further, calling on people to join labor unions with an eye toward future strikes, and to resist a feared crackdown on Hong Kong educators who have links to the movement.
Many marchers gave money at a booth set up by Spark Alliance, a fund that has raised millions of dollars to provide legal support and other kinds of aid to protesters. The donations were in defiance of a police operation last month, in which four people were arrested on suspicion of money laundering and $9 million of the fund’s assets were frozen.
On Wednesday, at least five people were detained for vandalizing a glass door and ATMs at a branch of HSBC, which had shut down Spark Alliance’s account. Banks and businesses that are perceived to have links to mainland China or the Hong Kong government have been targeted for vandalism or boycotts by some protesters.
One witness, Kan Cheng, said she saw as many as nine undercover police officers beating two young people near the bank’s broken door.
“I saw a protester being beaten and she hadn’t done anything at all,” said Ms. Cheng, 60. “She hadn’t vandalized at all.”
For the city’s leadership, the protests are the biggest political crisis since the handover from Britain. Hong Kong’s chief executive, Carrie Lam, has struggled to deal with the unrest while also satisfying her superiors in Beijing.
On New Year’s Eve, Mrs. Lam addressed the territory and called for calm ahead of the protest. “Let’s start 2020 with a new resolution, to restore order and harmony in society. So we can begin again, together,” she said in a video message.
“We must handle the problems at hand and acknowledge the shortcomings in our systems as well as the deep-rooted problems and conflicts that have been accumulating for many years in our society,” she said.
Mrs. Lam, who introduced and eventually withdrew the extradition bill that set off the protests, has promised to address social and economic issues that she says underlie the unrest. But the government said in a statement on Wednesday that “the top priority now is to stop violence and restore social order as soon as possible so that the daily lives of people and various business activities can return to the normal track.”
It is a message that has been echoed in Beijing. China’s top leader, Xi Jinping, who has permitted a degree of public protest in Hong Kong that is unheard-of on the mainland, mentioned the protests in his New Year’s Day address, saying that “Hong Kong’s prosperity and stability is the wish of Hong Kong compatriots and the expectation for the people of the motherland.”
Reporting was contributed by Ezra Cheung, Katherine Li and Jamie Tarabay from Hong Kong, and Chris Buckley from Beijing.