HONG KONG — Six months ago, more than a million people marched through Hong Kong in what became the start of a sustained pro-democracy movement against Beijing’s tightening grip on the territory.

On Sunday, they did it again.

Hundreds of thousands of people showed up in the park where the movement began in June, waving signs calling for the end of Chinese Communist Party rule and for the Hong Kong government to meet protesters’ four outstanding demands. The march, approved by authorities, was one of the biggest peaceful protests in the city in months — organizers counted at least 800,000 participants — and demonstrated the strong support that still exists for greater democratic freedoms despite a crackdown in which police have fired more than 10,000 tear gas canisters and arrested about 6,000 people.

It was also an indication that increased violence by protesters that reached a peak in November has not deterred the “wo, lei, fei” — the peaceful, reasonable, nonviolent protesters who continue to demonstrate in solidarity with the more radical front-liners.

“We want to show that the spirit of Hong Kong people is the same, that it won’t change despite all the actions done by the police and the government to stop us and suppress us,” said Mike Cheung, a 25-year old protester waiting in Victoria Park for the growing crowd to begin their march. “We still have hope, no matter what.”

In the first few weeks of November, the protest movement reached a dangerous new level as protesters tried to hold two university campuses against police incursions, leading to a siege in which both sides used force. Protesters rained gasoline bombs down on police, who in turn fired tear gas and threatened to use live rounds.

But the movement in recent weeks scored two key victories: a resounding vote of confidence at the ballot box, where pro-democracy parties won a huge majority of seats in local elections, and the passage of a U.S. bill to expose those who restrict Hong Kong’s freedoms to sanctions.

The protests were sparked in June by legislation that would have allowed the extradition of criminal defendants to mainland China. The Hong Kong government formally withdrew that proposal in October, but it has made no indication that it will meet any of the protesters’ other demands, which include an independent investigation into police conduct and the long-held goal of direct elections for Hong Kong leaders.

A 23-year-old protester, who wanted to use only her first name, Violet, for fear of repercussions from her employer, said she has been discouraged by the apparent futility of mass demonstrations like Sunday’s.

“Sometimes it almost feels like we are Sisyphus trying to push the rock up the mountain, even though it keeps rolling back on us,” Violet said. “Being here is the right thing to do.”

The crowd that gathered in Victoria Park was almost festive, in contrast to the tensions that have marked protests for months. Participants showed off artistic posters portraying local flash points over the past six months. Several groups distributed Christmas cards and asked attendees to write messages of support to the dozens of detained protesters who have been denied bail.

“Even though it is the festive season, we have to remember our brothers and sisters still in jail and tell them that we remember their sacrifices,” said Christine Chan, 23, as she handed out the cards and colored pens.

By night, small groups of protesters had set up barricades in front of lines of riot police. Graffiti marked almost the entire route of the march. A few businesses perceived to be pro-Beijing and Chinese banks were vandalized, as was the territory’s High Court.

The rally was organized by the Civil Human Rights Front, the group that organized the earlier marches that drew millions of people. Ahead of the protest, the group urged demonstrators to remain peaceful, a hallmark of its rallies. The group said it had timed the march for international Human Rights Day on Tuesday.

“The human rights violations and humanitarian crisis in Hong Kong and China are reaching a tipping point now,” the group said, expressing solidarity with the Muslim Uighur minority who have been placed in mass detention camps in western China. “Our rally today is to gather everyone in Hong Kong to defend our city, as well as [to advance] the international human rights movement.”

Beijing views U.S. support for the protest movement as a deliberate provocation, and authorities have accused “foreign actors” of stoking unrest in Hong Kong to destabilize China. On Monday, China said it would impose sanctions on U.S.-based nonprofit organizations including the National Endowment for Democracy and Human Rights Watch in retaliation for the pro-Hong Kong legislation.

“They bear great responsibility for the current chaos in Hong Kong,” Foreign Ministry spokeswoman Hua Chunying said. “These organizations deserve to be sanctioned, and they must pay the price for it.”

The statements appeared to have little connection with the scenes on Sunday. By nightfall, people of all ages continued to make their way from the park — more than three hours after the march began — filling the streets with chants of, “Five demands, not one less!”

“We know that achieving democracy takes a very long time, especially since we are against the biggest dictator in the world right now,” Violet said. “But most of us have made ourselves ready for a long fight.”