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.

Also read:Shanghai re-tightens on COVID, frustrating trapped residents

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 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.

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

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