HONG KONG — Hundreds of thousands of demonstrators marched in peaceful protest in Hong Kong on Monday (July 1) as it commemorated its return to China in 1997, but the city was shaken by images of a smaller group of activists who broke into the legislature, smashed glass walls and spray-painted slogans in the inner chamber.

The split-screen protest offered vivid evidence that the divide in the former British colony is not merely between protesters and the Beijing-allied government — the protesters are increasingly at odds with one another.

On Monday, as activists armed with metal bars and makeshift battering rams were on the cusp of breaking down the doors of the Legislative Council, a group of veteran politicians sympathetic to their cause pleaded with them to reconsider.

Some were shaking their heads. Some were on their knees.

“Please ask if it’s worth it,” Ms Claudia Mo, a lawmaker, told one black-masked protester. “Think about your mother.”

The confrontation made clear that the protest movement that has upended Hong Kong for months as citizens condemned meddling from the mainland is at a crossroads. Until now, protesters took pride in having no recognised leaders and using encrypted messaging to crowdsource their direction.

But the pitfalls of that approach have begun to emerge, with protesters disagreeing over tactics and goals and lacking a consistent position from which to negotiate — even as the government toughens its stance.

“Now Beijing has a good excuse to become even more uncompromising,” said Dr Jean-Pierre Cabestan, a political scientist at Hong Kong Baptist University.

On Monday, Hong Kong social media was filled with pleas for the protesters to return to nondestructive methods. And early Tuesday, Ms Carrie Lam, Hong Kong’s chief executive, condemned the violence and praised the police, who she said had exercised restraint.

For weeks, the Hong Kong protest movement had stayed on the high road.

A few days after police used rubber bullets and pepper spray against demonstrators June 12, protesters held a vast and peaceful demonstration of more than 2 million, even though the government had suspended consideration of a bill that would allow extraditions to mainland China.

Since then, smaller demonstrations have continued, without seeming to alienate the business community or lose focus.

On Monday, the vast majority of protesters were once again peaceful. But the images that dominated the day were generated by a core of a few hundred protesters who broke into the legislature.

The protesters now risk helping President Xi Jinping of China justify his desire for tighter control of Hong Kong, analysts say. Some say the protesters are overreaching, as they did during similar protests five years ago, when critics of the government rejected a compromise by Beijing and ended up with nothing.

The unrest was a sharp challenge not only to Hong Kong’s leaders but also to Mr Xi, who has sought to expand Beijing’s influence in the semiautonomous territory but now faces a turbulent political crisis with no signs of abating. The protest Monday represented a brazen defiance of Beijing’s rule and was a dramatic display of the challenge that the party faces in winning over Hong Kong’s youth.

The protesters’ rejection of the pleas of sympathetic lawmakers as well highlights their deep disillusionment with Hong Kong’s political system. Many are skeptical that lawmakers, even those who embrace their cause and attend their rallies, have their interests at heart.

The distrust speaks to a widening gulf between the city’s political class and its youth, who feel that older generations have been too eager to compromise with Beijing and allowed the Communist Party to chip away at Hong Kong’s freedoms.

Since early June, protesters, many of them students, have urged the government to withdraw the extradition bill.

Responding to pressure from protesters, Hong Kong’s leader, Ms Lam, suspended the bill last month and apologised. But the protesters remain unsatisfied, demanding the bill be withdrawn entirely and that Ms Lam resign.

Demonstrators poured into the streets Monday, the anniversary of Hong Kong’s handover from Britain to China in 1997, a traditional day of protest for people who oppose China’s tightening grip.

In the morning, Ms Lam clinked glasses of Champagne with other Hong Kong officials as they celebrated the 22nd anniversary and watched on video displays as the flags of China and Hong Kong were raised in tandem outside the city’s harbour-front convention center.

But tensions erupted almost immediately. Hundreds of riot police officers used batons and pepper spray to beat back demonstrators who had gathered nearby. Many protesters were angered by the police’s response and marched to the offices of the Legislative Council, where they used metal rods and carts to break the building’s glass facade.

At night, the protesters stormed into the legislature, building barricades inside and spraying messages on the walls calling for protesters who had been arrested last month to be released. “Murderous regime,” said one message.

The protest quickly became a broad repudiation of Chinese rule, with demonstrators tearing up copies of the Basic Law, a mini-constitution that took effect in 1997 and governs Hong Kong’s relations with Beijing, and calling for free and direct elections. One group raised a British, colonial-era flag.

“We need to let out our long-repressed emotions and to let the rest of the world know about this news,” said mr Kris Yeh, a 20-year-old protester who said he had helped smash glass doors and spray-paint walls.

Protesters mostly cleared out of the legislature after three hours of occupation. Then a cordon of riot police charged to disperse the crowd outside.

The confrontation at the legislature divided protesters. Some denounced the actions of the protesters who crashed into the building. Others were less critical, saying they could understand the anger.

“I don’t support violence, no matter what, but I understand why people would do it,” said Ms  Emily Lau, a former lawmaker. “They are very frustrated because they say they have protested so much.”

Some argued that nonviolence had failed and that a more confrontational approach was necessary to protect Hong Kong’s freedoms.

“We have been too peaceful for the past few times, so the police think we are easily bullied,” said Ms Natalie Fung, 28, who supported protesters with food and drinks outside the legislature. “The younger people are risking their safety and their futures for us.”

In Beijing, the state-run media mostly ignored the protests. But they were perceived among some as a stark challenge to Mr Xi’s rule, taking place on the 98th anniversary of the founding of the Communist Party of China.

The unrest has put Mr Xi, who has promoted an image as a tough, uncompromising leader, in a difficult position, as he grapples with the prospect of more clashes between police and protesters, or removing Ms Lam, a chief executive whom he swore in two years ago.

Still, mainland experts said the chaos Monday might give the central government confidence that the movement in Hong Kong was unraveling and could fade on its own.

“This movement has reached its end,” said Mr Tian Feilong, executive director of a research institute on Hong Kong policy in Beijing, citing the divisions between lawmakers and more extreme protesters. “It will cool down by itself.”

Beijing already has a formidable network of sympathetic business executives, media outlets and civil servants in Hong Kong. But the political crisis might prompt officials to place even greater pressure on those groups, experts say, such as by threatening employees of mainland companies whose children participate in the protests.

“Those elements will be pushed to the max to elicit greater compliance from the population,” said Professor Victor Shih, an associate professor of political economy at the University of California, San Diego.

The movement now enters a period of uncertainty. Arrests are likely. Divisions are growing among protesters. Without a recognised set of leaders, the demonstrations lack a sense of focus.

For many, the situation has rekindled memories of the campaign that became known as the Umbrella Revolution in 2014, an 11-week protest for free elections. The movement eventually fractured.

Professor Victoria Hui, an associate professor who studies Hong Kong politics at the University of Notre Dame, said a successful protest required some level of coordination, even if it was decentralised.

“It cannot be leaderless,” she said. “They need better coordination. It’s not worth it to court arrest.” THE NEW YORK TIMES