HONG KONG — Tens of thousands of pro-democracy demonstrators marched over police objections and occupied central thoroughfares in Hong Kong on Sunday, punctuating a weekend that included fistfights between people on opposing sides of the city’s yawning political divide.
The turnout at the Sunday march was lower than that of similar marches this summer, including one that organizers say drew two million people. But the demonstration showed the staying power of a movement that has produced 15 consecutive weekends of unrest in a global financial hub known for order and efficiency.
The marching and scuffling came just over two weeks before a major political moment on Oct. 1: the 70th anniversary of modern China’s founding. A key question is what protesters will do on that date, and how Beijing and the Hong Kong police will respond.
“I don’t think the government will be able to respond to our demands by Oct. 1, so people will keep fighting for what they want,” Cheng Sui-ting, 27, an environmental educator, said at Sunday’s march, which began in the Causeway Bay shopping district and quickly stopped traffic.
Carrie Lam, Hong Kong’s beleaguered leader, said early this month that she would formally withdraw the contentious extradition bill that prompted the initial protests in June and led to the territory’s worst political crisis since it returned to Chinese control in 1997.
But mass rallies have continued, in part because the movement’s demands have gradually expanded to include broad calls for political reform, including universal suffrage, and an independent inquiry into allegations of police brutality.
This weekend, some protesters said they were primarily motivated by grievances with the Hong Kong police over their crowd-control tactics, including the widespread use of tear gas, pepper spray and rubber bullets.
“Police aren’t doing themselves a favor by continuing to damage the public’s opinion of them,” said Yoyo Leung, 20, a university student who attended an unauthorized rally in northwestern Hong Kong on Saturday with her parents and siblings. She added that, at least in the short term, “there’s no way they can rebuild people’s trust.”
Other protesters seemed bent on confronting government supporters who were vandalizing the so-called Lennon Walls that the movement has set up across the city for pro-democracy messages and artwork.
And at a mall on the other side of Hong Kong’s harbor, a fight broke out between pro-democracy groups and pro-Beijing demonstrators who had gathered to sing the Chinese national anthem and waive Chinese flags.
The Hong Kong Hospital Authority said that at least 25 people had been hospitalized with injuries sustained in the scuffles on Saturday.
On Sunday, major department stores in Causeway Bay and several stations along the city’s primary subway line were closed as black-clad demonstrators marched down a thoroughfare singing “Glory to Hong Kong,” their new protest anthem.
The police force warned on Twitter that people who were blocking roads in Causeway Bay were participating in an “unauthorized assembly.” It asked people in the area to leave immediately.
Days earlier, an established Hong Kong advocacy group, the Civil Human Rights Front, had applied for a permit to hold the march legally. But the police rejected the request, citing concerns for public safety, and the group officially canceled the march.
But many protesters have been ignoring such bans for weeks now.
“I come out because it is my right, and I don’t care whether the police agree or not,” said Joesy Lau, 53, a clerk at an investment firm. “It’s my right.”
Sunday’s march followed days of smaller pro-democracy rallies around the city, including a politically tinged light display that coincided with the Mid-Autumn Festival, a Chinese holiday that celebrates the harvest and normally features colorful lanterns.
Ms. Cheng, the environmental educator, said that the turnout at the march did not reflect the full range of participation in the pro-democracy movement. “I believe people are using different means to fight for their demands,” she said.
The march came a week after a rally outside the American Consulate descended into violence.
That rally began peacefully, as hundreds of thousands gathered to drum up support for a bill moving through the United States Congress that would, among other things, require an annual justification for why the United States should offer Hong Kong special trade and business privileges.
But within hours, hard-core demonstrators on the fringes of the rally smashed windows and vandalized Central Station, a vital transit hub for shoppers and commuters. Police officers in riot gear later made arrests across the city, and sprayed tear gas in Causeway Bay to disperse protest crowds.
A few days later, Mrs. Lam, Hong Kong’s leader, said it was “extremely inappropriate for foreign parliaments to interfere” in the city’s internal affairs.
Mrs. Lam also said that Hong Kong would not allow the United States to become a “stakeholder” in discussions about the city’s status as a special administrative region of China, a feature of the framework under which the city has been governed since British colonial rule ended in 1997.
Before the march on Sunday, a few dozen protesters gathered outside the British Consulate to ask London to take action against Beijing for what they called violations of the Sino-British Joint Declaration, the 1984 agreement that laid out Hong Kong’s future under Chinese rule.