In response to a small number of COVID cases, authorities in China's southern city of Shenzhen shut down the world's largest electronics market and suspended public transportation in the surrounding area on Monday.

According to the district government, Huaqiangbei, a popular shopping center with thousands of shops selling computer components, mobile phone parts, and microchips, is one of three neighborhoods in the Futian district that have been placed under a required four-day lockdown. Residents in those areas are not allowed to leave their houses except for COVID testing, which they must do every day until Thursday.

Except for supermarkets, pharmacies, and hospitals, all businesses in the impacted areas are closed through Thursday. Restaurant dining is also prohibited, with only takeout permitted.

China is one of the few countries still enforcing severe zero-COVID policies, which rely on broad digital surveillance, mass testing, massive quarantines, and emergency lockdowns. Shenzhen, an international technology hub with a population of 18 million people, reported only 35 infections on Tuesday, including 11 asymptomatic cases.

The heavy-handed approach has resulted in the designation of dozens of communities in Shenzhen as "high-risk areas" and the imposition of tight lockdown restrictions. Inhabitants' social media posts show metal obstacles, some topped with barbed wire, installed outside residential structures, preventing residents from leaving.

Additionally, all public parks and amusement venues were closed in the districts of Luohu and Longgang, and events like conferences, performances, and square dancing were prohibited.

In addition, 24 subway stations and hundreds of bus stops in Shenzhen, notably those near the Huaqiangbei electronics market, had service suspended by the authorities.

Officials from Shenzhen stated at a news conference on Monday that the new subvariant Omicron BF.15, which is more contagious and difficult to detect, is the major cause of the outbreak. "The upcoming period will be the most stressful, high-risk, and grim period for epidemic prevention and control in our city," a Shenzhen official told the news conference.

The extremely contagious Omicron variety has presented mounting difficulties for China's zero-COVID approach, forcing rolling lockdowns and daily testing in large sections of the nation. Constant limitations have disrupted daily living and taken a significant toll on the economy, which is already slowing. One out of every five young people in China were unemployed in July which hit a record high.

COVID outbreaks in the western Chinese provinces of Xinjiang and Tibet earlier this month kept tens of thousands of travelers trapped. Authorities in the southern metropolis of Chongqing ordered widespread COVID testing during a record heat wave, exposing millions of citizens to endure hours-long exposure to the sun while battling high temperatures and power outages.