Good morning.

       We’re covering a lockdown in Xinjiang, Beijing’s high-tech tactics in Hong Kong and the U.K.’s strategy to restart its restaurant industry.

       Xinjiang lockdown: ‘Prevention or suppression?’ For 40 days, millions of people in the western Chinese city of Urumqi have been under lockdown, confined to their apartments.

       Officials say it’s to prevent a resurgence of the coronavirus, but cases seem to be under control, with no local transmission in nine days. Residents have posted videos of people handcuffed to metal posts for breaking quarantine rules, and of people yelling from their homes in despair.

       There are persistent concerns about human rights abuses in Xinjiang, where the government has sent up to one million Uighur Muslims to internment camps. Activists worry the pandemic is being used to expand the crackdown.

       The restrictions began in mid-July as dozens of people got sick with Covid-19. Thousands of police officers were dispatched to impose a lockdown in several cities in what officials called a “wartime campaign.” For some, it now feels indefinite.

       Here are the latest updates and maps of the pandemic.

       In other developments:

       Two more cases of reinfection with the coronavirus were reported in Europe on Tuesday, a day after a 33-year-old man in Hong Kong was confirmed to have been infected a second time.

       Seoul closed schools and switched to online classes again as South Korea reported 280 new cases on Tuesday, the 12th-straight day of triple-digit daily increases in virus infections.

       Hong Kong on Tuesday announced plans to begin easing its social-distancing rules, and its leader dismissed privacy concerns about a Beijing-led testing program throughout the city.

       Beijing’s Hong Kong crackdown goes high-tech With the help of the national security law, Hong Kong police are targeting the social media accounts of executives, politicians and activists.

       Their approaches — from sophisticated cyberattacks to installing a camera outside the home of a prominent politician — look similar to the ones used by China’s secret police.

       Residents and foreign internet giants are struggling to respond. Activists put out cybersecurity tutorials, and people have flocked to encrypted messaging services. Companies like Facebook, Twitter, Google and Yahoo have cut off data sharing with the police or implemented other protections.

       Quotable: “The problem is this slows everything down, because now everyone is double checking: ‘Did you send this message? Did you send that?’ It never stops,” said an executive at Next Digital who got a suspicious message asking for information about the media mogul Jimmy Lai.

       Ant Group files to go public The payment- and finance-focused sister company of the e-commerce giant Alibaba filed on Tuesday to list shares in Hong Kong and Shanghai, the first steps toward what could be a blockbuster initial public offering.

       Online finance has exploded in China, and Ant’s flagship service, Alipay, with 900 million users, has been a key driver. Filings did not indicate how much Ant hoped to raise, but they did give investors a detailed look at its major financials.

       What we learned: Ant said it generated $17 billion in revenue last year, a jump of more than 40 percent from 2018.

       Context: The company’s choice of Chinese exchanges over American ones is meant to capitalize on the interest of local investors, for whom Alipay is a household name. But it also reflects heightened tensions and worsening prospects for Chinese technology firms in the U.S.

       If you have 6 minutes, this is worth it How the U.K. restarted its restaurant industry

       When the British government told people they no longer had to stay home, it needed a persuasive pitch to get everyone back outside and, crucially, spending money. The answer: half-price restaurant meals, subsidized by the government on certain days of the week. “Last Wednesday, my God, was pandemonium,” said the owner of a food market in Liverpool.

       Britons eager for a bargain have taken up the offer, and restaurants are grateful for the rush of customers. But now some wonder how sustainable the recovery will be when it gets too cold for outdoor dining — especially with a wave of layoffs expected.

       Here’s what else is happening Thailand: Facebook is planning legal action against the government for ordering the social media platform to partly shut down access to a group critical of the monarchy. The group, Royalist Marketplace, has more than a million members and was set up by a self-exiled Thai academic living in Japan.

       Drinking culture: After a bank employee in Beijing refused a drink at a company dinner, an executive at his company slapped him. The episode went viral and ignited a conversation on China’s drinking culture.

       China trade: U.S. negotiators discussed the status of the deal that was signed in January, even as relations deteriorate in other areas.

       U.S. presidential election: On the first night of the Republican National Convention, President Trump and his allies presented a bleak vision of the country’s future under a Biden administration. Here are our reporters’ takes on the moments that mattered.

       Snapshot: Above, Gaulien Smith, who owns Gee’s Clippers, a barbershop in Milwaukee. Our reporter visited Wisconsin, a swing state, and spoke with a dozen Black men and elected officials about voter turnout in this year’s presidential election. For Democrats, gaining the support of Black men is a major focus.

       What we’re reading: Adam Pasick, on the Briefings team, recommends this deep dive into infrastructure planning by Aaron Gordon of Vice, who examined a deeply flawed model that has been used to falsely justify billions of dollars in highways and bridges.

       Now, a break from the news

       Cook: This ginger lime chicken may look basic, but don’t be fooled — it’s buzzing with bright flavors, and a secret ingredient: mayonnaise.

       Listen: Bettye LaVette has a heartfelt collection of songs that were originally popularized by Nina Simone, Dinah Washington and other Black singers.

       Watch: “The Vow,” an HBO documentary series about the cult Nxivm, which goes down a dark path to examine why people fall for psychological traps.

       At Home has our full collection of ideas on what to read, cook, watch and do while staying safe at home.

       And now for the Back Story on … The hottest parts of town

       Decades of racist urban policy in the U.S. have left some minority neighborhoods up to 20 degrees hotter than wealthier, whiter parts of the same city. Natasha Frost, on the Briefings team, talked to Nadja Popovich, a graphics reporter on the Climate desk, about redlining and urban heat disparities.

       What brought you to this idea initially?

       There’s this idea of the “urban heat island” effect, which we traditionally think of as cities being much hotter than the surrounding countryside. But actually, there’s a really unequal urban heatscape within cities, which poses a pretty huge problem for people’s health. We reported on this last year, but we didn’t get deep into the reasons that the disparity exists.

       Now, some new research has started to unravel how historical housing and other urban planning policies that were often quite explicitly racist helped create the urban heat environment in cities across the U.S. We ended up focusing specifically on Richmond, because we found it to be a really compelling example of some of these practices.

       Were residents aware of these disparities?

       One woman we spoke to told us that she walks her two boys a mile and a half to a cooler, leafier park in a wealthier part of town instead of letting them play out in the glaring sun at the local playground. Others are definitely not as aware. When you get your local weather, you get one number for the whole city — not these really local pictures of what the temperature is in different parts of the city.

       How did you approach the challenge of capturing heat visually?

       Visualizing heat is a unique challenge, especially for photography. So for this piece, we wanted to lead it with maps that use satellite data to show heat disparity. We then overlaid them with historical redlining maps to show people how these government-imposed policies overlap, quite literally, with the urban heatscape today.

       We also worked with a really great photographer, Brian Palmer, who’s actually based in Richmond, Virginia, to show the human side of the story. He took amazing, beautiful photos, both of families we had spoken to who are impacted by the heat, and also of the difference in neighborhoods, to show people what abundant tree canopy cover looks like in the cooler neighborhoods, and also what having so much pavement in a neighborhood and no shade really looks like.

       That’s it for this briefing. See you next time.

       — Melina

       Thank you

       To Theodore Kim and Jahaan Singh for the break from the news. You can reach the team at briefing@nytimes.com.

       P.S.

       ？ We’re listening to “The Daily.” Our latest episode is about where the U.S. stands on the pandemic.

       ？ Here’s our Mini Crossword, and a clue: Animal whose song can travel thousands of miles (five letters). You can find all our puzzles here.

       ？ Coverage in The Times won seven awards from the New York Press Club, including work from Metro, Culture and Science. Jodi Kantor and Megan Twohey won a special award.