(CNN) The Chinese metropolis of Wuhan has shut down a district of almost a million people after detecting four asymptomatic Covid cases, as the original epicenter of the pandemic takes no chances in preventing another outbreak under China's stringent zero-Covid policy.
Authorities in Wuhan's Jiangxia district, home to more than 970,000 people, announced Wednesday its main urban areas would enforce three days of "temporary control measures."
Entertainment venues -- including bars, cinemas and internet cafes -- small clinics and agricultural product marketplaces were closed; restaurant dining and large gatherings, from performances to conferences, were suspended; all places of worship were shut and religious activities banned; while tutoring institutions and tourist attractions halted operations, according to a government statement.
All public transport, from buses to subway services, were suspended, and residents were urged not to leave the district unless absolutely necessary.
Authorities also identified four high-risk neighborhoods where residents are banned from leaving their homes. A further four neighborhoods were designated as medium-risk, meaning residents cannot leave their compounds.
The measures were aimed to "further reduce the flow of people, lower the risk of cross-infection and achieve dynamic zero-Covid in the shortest time possible," the statement said.
The sweeping restrictions came shortly after Jiangxia district authorities announced the discovery of four asymptomatic infections late on Tuesday. Two were detected during regular testing drives, while the other two were found among their close contacts.
Wuhan, a transport and industrial hub in central China's Hubei province, imposed the world's first Covid lockdown in early 2020 to contain the rampaging coronavirus, after initially playing down the outbreak and silencing health workers who tried to sound alarms.
The stringent lockdown shuttered businesses and confined residents to their homes for more than two months. The paralyzing lockdown came at a huge personal cost to residents, but eventually succeeded in taming the virus.
Despite the initial mishandling, the Chinese government has heralded Wuhan as a success story in its fight against the pandemic. In August 2020, as much of the world grappled with Covid-19, Wuhan made international headlines when it held an electronic music festival in an open air water park, with thousands of people partying without any masks or social distancing measures in sight.
Meanwhile, the stringent measures of snap lockdown, mass testing and strict quarantine have been used by authorities across China to contain sporadic outbreaks, in what has become known as the zero-Covid strategy.
That approach had been mostly effective in curbing China's Covid flare-ups until this year, when the highly transmissible Omicron variant caused the country's largest outbreak since Wuhan.
The financial hub of Shanghai was placed under more than two months of bruising lockdown, sparking public outcry over widespread food shortages and delayed medical care for emergency patients. Cities and towns around the country have also been subject to varying degrees of restrictions as infections flare, with some border towns undergoing intermittent lockdowns for months on end.
The lockdowns have also wreaked extensive damage on the Chinese economy, plunging it into the slowest quarterly growth since the start of the pandemic.
As much of the world moved on from the pandemic, Chinese officials, including the country's leader Xi Jinping, have repeatedly vowed to stick to the zero-Covid policy, citing the low vaccination rate among the elderly.