HONG KONG — Police banned the march. Two of its promoters were attacked.
Still, crowds of black-clad protesters filled the streets of Hong Kong on Sunday in a display of continuing support for the monthslong protest movement despite increasing restrictions from the authorities. The march, which passed some of the most prominent centers of Hong Kong’s South Asian community, also featured a call for solidarity with the city’s ethnic minorities.
The demonstration began peacefully, eventually punctuated by outbursts of vandalism to shops, bank branches and subway stations. In a reprise of the clashes that have grown common, protesters threw firebombs at the police and officers fired multiple rounds of tear gas at demonstrators.
And there were hints of possible escalations in violence. The police used a robot to dispose of a suspected homemade bomb on a street in the Prince Edward neighborhood. It was not immediately clear what danger, if any, the object posed.
One week ago, the police said that a homemade bomb was detonated, a first for the protests. The explosive device, which was set off by a mobile phone, did not harm anyone.
Demonstrators started in Tsim Sha Tsui, a crowded commercial district on the southern tip of the Kowloon Peninsula. They assembled along a promenade beside Victoria Harbor and chanted slogans while the protest anthem “Glory to Hong Kong” was played.
The Hong Kong subway system, which has sustained widespread vandalism from protesters in recent weeks, closed stations near the march’s route. Protesters broke windows in several stations on Sunday and painted graffiti over the protective barriers installed around the entryways. Branches of Chinese-owned banks and outlets of companies seen as hostile to the protest movement were also damaged.
The Civil Human Rights Front, the organizer of large, peaceful marches this summer it estimated were attended by up to two million people, applied to host the event Sunday. But the police rejected the application, saying that such demonstrations have often been hijacked by vandalism and violence.
After the ban, the group backed out of hosting the march, but one of its leaders, Figo Chan, and other pro-democracy figures called on people to turn out anyway.
“I’m not afraid of arrest, of jail, of getting beaten up or gashed,” Mr. Chan said Sunday before the march. “But I hope people understand that to fight for democracy, freedom and justice, we must sacrifice. We use peaceful, rational and nonviolent means to express our demands. We are not afraid of arrest. What I fear most is everyone giving up on our principles.”
Another Civil Human Rights Front leader, Jimmy Sham, was attacked by men with hammers on Tuesday in Kowloon. Mr. Sham was released from a hospital, but was continuing to receive treatment and not able to attend the march, the group said.
That attack led to expressions of support for Hong Kong’s ethnic minority communities during the protest Sunday. Some unconfirmed reports said Mr. Sham’s attackers were paid South Asian men, and people in the protest movement said they were worried that could lead to retaliatory attacks.
Some demonstrators on Sunday stood outside the Kowloon Mosque and Islamic Center with signs calling on others to respect the building. “Be nice to religion,” one sign read.
As the police water canon moved past the mosque, its gate and steps were doused with a stinging blue liquid that officers sprayed at protesters holding signs outside.
“What can we say?” said Yaz Bhutta, a 28-year-old salesman, throwing his hands in exasperation after seeing the stained steps. “The police are crazy people, spraying chemicals at our mosque. This is where we come and worship every day.”
Picking up a broom, he brushed streams of the blue liquid into drains.
The police said the spraying of the mosque entrance had been an accident, and contacted the chief imam and Muslim community leaders to explain and express concern.
At Chungking Mansions, a building in Tsim Sha Tsui that holds several South Asian-run restaurants and shops, volunteers handed out bottled water to demonstrators.
Kamil Kaka, who is from southern India and has lived in Hong Kong for more than a decade, said he was a little worried that protesters could target South Asians like him.
But Mr. Kaka, 32, said he thought Hong Kong people should have a right to protest, as he stood on a side street in Tsim Sha Tsui, watching demonstrators stream down the district’s main thoroughfare.
“People are fighting for their freedom,” Mr. Kaka said.
After the attack on Mr. Sham, another protest supporter was seriously injured in an assault on Saturday evening. A 19-year-old man was stabbed in the neck and abdomen near a subway station in northern Hong Kong as he distributed fliers calling on people to join the march. He is hospitalized in serious condition, the government said.
A 22-year-old man was arrested in the attack. The local news media quoted witnesses who said the attacker had shouted that Hong Kong was a part of China, and that protesters were damaging the city.
Chinese officials and the state news media have denounced the protests as a separatist movement. Some Hong Kong marchers carried Catalan flags on Sunday to show solidarity with the separatist movement in Spain. Although some protesters have called for Hong Kong’s independence from China, it is not a focus of the Hong Kong demonstrators or one of their official demands.
The protests began over legislation, since withdrawn, that would have allowed extraditions to mainland China from Hong Kong. Hong Kong’s top leader, Chief Executive Carrie Lam, said in September that the government would withdraw the proposal, but public anger with the authorities has remained high.
The marchers on Sunday reiterated other longstanding demands, including an independent investigation of the police, amnesty for arrested protesters and the introduction of direct elections for the chief executive and the entire legislature.
The organizers have also raised two newer demands: a reorganization of the police department and the scrapping of a ban on face masks.
Mrs. Lam used emergency powers this month to introduce the mask law. The move set off a wave of fresh protests and clashes with the police.
“I want to make the best use of every chance to come out,” said Anne Chin, 32, a clerk who joined the march. “After the mask ban, we don’t know when the government will invoke the Emergency Regulations Ordinance again and implement laws that may further muzzle Hong Kong people’s rights.”
Mr. Chan said at least 350,000 people participated in the protest.
Protesters said they were determined to show that the movement still had wide support, even if the attendance had been dampened by police bans and recent attacks. Jason Wong, a 26-year-old office worker, brought to the march 60-foot-long black banners signed by residents in each of the city’s 18 districts with colorful markers, an effort aided by a team of volunteers.
“The government has posed many restrictions and tried to oppress the Hong Kong people, but we cannot show weakness,” he said. “We need to show the world that we have many people calling for common demands, even if not everyone dares to come out.”
Reporting was contributed by Ezra Cheung, Elaine Yu, Javier Hernández and Tiffany May.