The lockdown, which came after virus cases doubled nationwide to nearly 3,400, will be accompanied by three rounds of city-wide, mass testing, according to a government notice.
The measure, announced Sunday, followed earlier restrictions placed on Shenzhen’s central business district, and will last until March 20.
All bus and subway systems were shut, and businesses, except those providing essential services, have been closed.
The city is home to the China headquarters and a key manufacturing facility of Hon Hai Precision Industry Co., Apple Inc.’s main maker of the iPhone and other products.
A Covid flareup in Shanghai has also seen most schools returned to online learning and travel into the city restricted.
China’s aviation regulator is in discussions with airlines about diverting all international flights into the financial center, Bloomberg News reported Friday.