The incident is the latest in a series of chaotic flash lockdowns enforced in recent weeks across China – one of the last countries in the world to still adhere to a "zero-Covid" policy.
Residents in various provinces have without warning found themselves held in places such as beach resorts, gyms and hotpot restaurants. Some have sought to escape by scaling fences, sprinting down beaches and pouring out of office buildings.
Shanghai, one of China's wealthiest and most cosmopolitan cities, has been the site of some of its most traumatic Covid curbs. Its 25 million residents experienced a severe two-month lockdown earlier this year amid food shortages and occasional clashes with authorities.
Zhao Dandan, the deputy director of Shanghai's Health Commission, said the Ikea store's sudden shutdown was ordered because one of the visitors had been a close contact of a six-year-old boy who tested positive for Covid after returning to Shanghai from Lhasa in Tibet, the site of one of China's biggest Covid outbreaks.
Mr Zhao that added those who were at the store and surrounding areas must quarantine for two days, followed by five days of health monitoring.
Nearly 400 close contacts of the six-year-old boy had been traced by Sunday, while 80,000 people had been ordered to take PCR tests, according to the Shanghai Daily.
An Ikea representative said the Xuhui store – the company's first to open in China – was closed due to Covid-19 at the request of health authorities, according to Bloomberg.
Chinese authorities use health monitoring apps to track and trace Covid patients and their close contacts. Residents are required to show "green" health codes in order to enter public spaces such as restaurants and shopping malls, and to board trains or flights.
China is continuing to enforce its zero-Covid policy, despite its severe effects on the economy and on people's wellbeing.
Health authorities reported 2,312 new infections nationwide on Monday, the first time in more than three months that cases topped 2,000 for three consecutive days.
Thousands of vacationers have been locked down for more than a week on the resort island of Hainan, where authorities suspended flights and shuttered businesses.
Dozens of tourists enacted protests at the Wyndham and Marriott Yalong Bay hotels, according to videos circulating on social media. Snap lockdowns have also been enacted in the southern technology hub of Shenzhen and in Chengdu, the capital of Sichuan province.