Radical protesters torched the Hong Kong headquarters of China’s state-run Xinhua News Agency after smashing plate glass windows in Wan Chai district on Saturday.

Hardcore demonstrators hurled bricks and petrol bombs and vandalized multiple subway stations and businesses perceived to be pro-China. Police responded with sustained volleys of tear gas, scattering protesters with water cannon trucks and making dozens of arrests.

Thousands of pro-democracy protesters defied authorities in another unsanctioned march after Beijing vowed to tighten control over the unrest-plagued city.

Commercial districts on Hong Kong island became a battleground as crowds of black-clad protesters, many wearing face masks despite a recent ban, clashed with riot police for hours.

Among those caught up in the tear-gas clouds were rugby fans who had gathered in bars in Wan Chai district to watch the World Cup final. Hours later revelers in a nightclub district had a similar experience as party-goers scrambled for cover and bars shut their windows.

By evening, the clashes had moved across the harbor to Mongkok and Tsim Sha Tsui, two areas that have seen regular skirmishes in recent months.

In a statement, Xinhua condemned the “barbaric acts” of the protesters who targeted their office.

The latest unrest came after China warned on Friday that it would not tolerate any challenge to Hong Kong’s governing system and planned to boost patriotic education in the city, which has seen 22 consecutive weekends of youth-led protests.

Hong Kong has been upended by the huge, often violent, pro-democracy protests which have battered the financial hub’s reputation for stability and helped plunge the city into recession.

One Hong Kong resident who is the head of a major investment bank expressed frustration at the ongoing unrest. “I’m very tired with these Hong Kongers. They’re so stupid and so violent and without any political sense and strategy. So is the so-called Hong Kong opposition.”

Beijing has shown no willingness to meet protester demands for greater democratic freedoms and police accountability – and activists show no sign of leaving the streets.

“The government and the police have been ignoring and suppressing the people’s demands so we need to continue the movement to show them we still want what we are asking for,” 18-year-old protester Gordon Tsoi, who was not wearing a mask, said as he marched.

“The entire government is being controlled by the central government now, so we have to come out to protect the freedoms we deserve,” added another 17-year-old protester who declined to give his name.

Police had rejected an application for an afternoon march, citing safety fears. But as often in the past, protesters simply defied the ban with thousands turning up before the clashes began.

After months of unrest, ideological polarization has exploded with protesters taunting police and officers returning the disdain.

In one video from Saturday, officers could be heard shouting that protesters were “cockroaches” and “sub-human”. Protesters routinely call police “triads.”

On Saturday afternoon, tens of thousands of people gathered in Victoria Park and Causeway Bay, demanding the government disband the police force and implement true universal suffrage. They also expressed their opposition to the emergency law and anti-mask law. Dozens of pro-democracy candidates for the District Council election showed up to meet their supporters in Victoria Park in the gathering, which had been banned by police.

People chanted slogans such as “Liberate Hong Kong, Revolution of our times!” and “Hong Kong people, rebel!”

At around 4pm, police fired many rounds of tear gas canisters at demonstrators, forcing them to move to Wan Chai. At the Southorn Playground, the police randomly arrested dozens of masked people for participating in an illegal assembly. There were several hundred demonstrators at the playground at that time. A helicopter hovered overhead for the entire afternoon.

The arrested protesters were tied up and held for more than two hours before they were bussed to the police station in North Point. Hundreds of masked protesters and residents had a highly vocal stand-off with police near the Southorn Playground.

Hui Chi-fung, a Democratic Party lawmaker, asked police to stay calm and avoid using tear gas near the residential area. Several police officers argued with Hui and residents before police fired rounds of tear gas at the crowd.

One officer told fellow officers, who were shouting at the crowd, to stay patient as they would be allowed to “show off” at the end of the operation.

Police used tear gas and deployed an armored vehicle and a water cannon truck. In a residential apartment in Wan Chai, the police arrested five people for storing 180 petrol bombs.

At around 7pm, masked people gathered in Causeway Bay again. Many rounds of tear gas canisters were fired. A first-aid attendant suffered serious burns to his back after he was hit by a burning tear gas canister.

A rally in Edinburgh Place and another in Charter Garden in Central on Saturday, which had previously been approved by the police, were cut short for safety reasons. Each of the gatherings was attended by several hundred people, who urged the US Congress to pass the Hong Kong Human Rights and Democracy Act.

During the day, some people set fire at the entrances of the MRT stations in Causeway Bay and Central. A total of 17 people were sent to hospitals, with one in serious condition and seven in stable condition.

In Tsim Sha Tsui, there were also serious clashes between demonstrators and police. Protesters set fires on roads and vandalized pro-Beijing shops. Police arrested many people in Mong Kok and dispersed the remaining with tear gas and water cannon. Clashes in various districts continued until midnight.