RUTHFULLY YOURS

A 70-year-old man died Thursday night after being hit in the head with a brick during a clash a day earlier. A 15-year-old boy was in critical condition on Wednesday, according to the Hospital Authority, which declined to comment on his current status. Local media said he sustained injuries after appearing to be hit in the head by a tear-gas canister. And police shot a 21-year-old protester on Monday; later, pro-democracy demonstrators set a man who argued with them on fire.

On Thursday in Brazil, Chinese President Xi Jinping urged a tough police response to the protests.

The Chinese government will “firmly support the Hong Kong police in strictly enforcing the law and firmly support the Hong Kong judicial bodies in severely punishing the violent criminals in accordance with the law,” Mr. Xi said. He made his comments on an international stage at a summit of leaders from emerging markets.

Clashes between protesters and police this week turned universities into battlefields, rendered highways and tunnels unusable, disrupted public transit and frequently left the city’s bustling financial district under a fog of tear gas. Shops across the city closed, further crippling an economy that has already tumbled into a recession. The Hang Seng Index, the city’s stock market, dropped 4.8%, its worst week since early August.

Schools shut down because of the violence and it isn’t certain if district council elections, scheduled for Nov. 24, can go forward.

Both sides have taken more aggressive stances in recent days, with black-clad youths throwing Molotov cocktails and bricks while police have made heavy use of tear gas, rubber bullets, batons and water cannons to try to disperse crowds. Police have arrested 653 people this week, ranging in age from 12 to 82.

In addition, a member of Chief Executive Carrie Lam’s cabinet was injured during a trip to London on Thursday after falling as protesters gathered around her.

The escalation in violence has hurt the already low public perception of police and risks additional erosion of support for the protesters. On Wednesday evening, demonstrators set a courthouse in the northern part of the city on fire, an attack that was condemned by the Hong Kong Bar Association.

“It is difficult to think of anything that is more corrosive to the rule of law,” the bar association said. “Attacks on private property are bad enough but if attacks on court buildings continue, the constitutional fabric of [Hong Kong] will be torn asunder with disastrous consequences for every Hong Kong resident.”

Government officials, including Ms. Lam, gathered Wednesday for a late-night meeting, although Matthew Cheung, the city’s chief secretary, described it the next day as an ordinary assembly. Mr. Cheung said it wasn’t the first time government officials met at night because of their busy schedules. He said Wednesday’s meeting was intended “to find ways to ease the current situation.”

Antony Dapiran, a lawyer and the author of a forthcoming book on the protests, said he has seen an increase in disruption this week to the everyday lives of people who aren’t involved in the protest movement.

“This anger is not subsiding. It seems to be getting worse,” he said, adding that the behavior of the police, the inaction of the government and comments from pro-Beijing politicians have inflamed the situation.

The protests, sparked earlier this year by a now-withdrawn bill that would have allowed suspects to be extradited to China for trial, have morphed into a broader antigovernment movement. Many demonstrators are focusing their anger on alleged police brutality. Paralyzing the city for an entire week marked an escalation in the protesters’ strategy, as they previously demonstrated mainly on weekends.

This week’s outpouring of anger was ignited by the death of a student from injuries caused by a fall from a parking garage close to where police had been using tear gas to disperse protesters.

Streets across the city were still filled with bricks Friday. Protesters had cemented some of them into place, building walls and other obstacles to block roads and slow police. Thousands of protesters spilled out into the financial district around lunchtime each day, using trash cans, bricks and traffic cones to build roadblocks.

Many companies told employees they could work from home. Goldman Sachs advised workers on Thursday to “exercise a high level of vigilance in the vicinity of any protests.”

In a video that circulated on social media, police appeared to arrest a man who said, “I work at Citibank, OK? My office is like 500 meters away from here.” A Citibank spokesman said: “We are aware of this incident and are investigating further. We expect all our employees to adhere to the law.”

Students turned several university campuses into battlezones. During Thursday’s morning commute, protesters at the Hong Kong Polytechnic University shot arrows at police officers, who responded with volleys of tear gas. Elsewhere, protesters stockpiled Molotov cocktails. At the Chinese University of Hong Kong—the fiercest front line of citywide clashes this week—protesters built a wall of bricks and spray painted the phrase, “All day all night we are gonna fight.”

Both universities had largely emptied out by Friday after they and others suspended classes for the rest of the semester, which ends in early December. Hundreds of mainland Chinese students fled across Hong Kong’s border into Shenzhen, seeking temporary shelter. Some said they were worried about their safety.

As for the hard-core protesters, the ones who left said they were resting for later demonstrations. At CUHK, the few hundred student protesters who remained were filling up commandeered trucks with donated supplies that they planned to store for later use.