BEIJING (AP) — The locked-down Chinese metropolis of Shanghai will reopen four of its 20 subway lines Sunday as it slowly eases pandemic restrictions that have kept most residents in their housing complexes for more than six weeks.

The city will also restart 273 bus lines connecting major urban centers, airports, train stations and hospitals as it resumes cross-district public transit, Yu Fulin, director of the Shanghai Transport Commission, said at a daily pandemic briefing Thursday.

It wasn’t immediately clear how frequent the service would be. Bus service resumed on a trial basis within three outlying districts this week, with buses running every 30 to 90 minutes during daylight hours.

The lockdown of China’s largest city has dealt a blow to the economy and frustrated residents, particularly as many countries elsewhere in the world move away from such harsh measures as they try to live with the virus. But officials have stuck to a “zero-COVID” approach, saying that lifting restrictions could strain the public health system and lead to more deaths, particularly among the not fully vaccinated elderly.

The outbreak in Shanghai has taken 580 lives, according to official statistics, making it the deadliest one in China since the initial outbreak in the city of Wuhan in early 2020.

Even as the number of new cases plummets, authorities are relaxing restrictions in a slow and deliberate manner as they try to ensure that the virus no longer spreads anywhere outside of quarantine facilities and areas with known infections.

The city of 25 million people recorded about 700 new cases on Wednesday, accounting for most of the about 1,000 cases nationwide.

Although most downtown areas remain in some form of lockdown, some of Shanghai’s outlying suburbs were showing signs of normalcy.

Residents in Jinshan district in the southwest could be seen shopping at a farmers’ market, buying grilled meat and bubble milk tea on a shop-lined street and getting haircuts, in video broadcast by the Shanghai Media Group.

Only 50 people were allowed in the market at a time, and stall owners were required to do one nucleic acid test and one antigen test each day. The market was also disinfected three times a day. Appointments were required for a haircut, and only two customers were allowed in the barbershop at the same time, the Shanghai Media Group said.

In Beijing, which reported 55 new cases, some subway stations and bus lines are closed, dining in restaurants is banned and residents are strongly encouraged to work from home as authorities try to prevent a Shanghai-scale outbreak in the Chinese capital.

Elsewhere in China, the city of Guang’an in southwestern Sichuan province was locked down on Wednesday. The province recorded about 150 new cases.

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Associated Press researcher Si Chen in Shanghai and video producer Caroline Chen in Guangzhou, China, contributed.

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