A residential complex in Shanghai's Yangpu District is fenced in amid the recent COVID-19 resurgence.

Shanghai reported three COVID-19 community cases on Tuesday and beefed up inspections of truck drivers along with mail and courier staff.

The asymptomatic cases, females aged between 18 and 33 years old, live in Yangpu District and outlying Jinshan District. They tested abnormal during recent regular polymerase chain reaction (PCR) screening.

Apart from their accommodations, the trio had been to a music school, beauty salon, cafe, foot massage shop, supermarket and pharmacy in Yangpu and Jinshan, according to the Shanghai Health Commission.

As a result, three areas, mainly their accommodations and some surrounding areas in Yangpu's Changhai Road Subdistrict and Jinshan's Tinglin Town were designated as medium risk and put under lockdown.

Shanghai reports three community cases on Tuesday.

Shanghai designates three medium-risk areas on Tuesday.

A total of 897 close contacts of the new cases have been traced and placed under central quarantine. Among them, 751 have tested negative. A total of 753,399 related people have been screened, and all tested negative.

Shanghai has enhanced inspections of cargo truck drivers coming from other provinces since Saturday, Shanghaifabu, the city's official WeChat account, said on Tuesday.

All cargo drivers and passengers must receive single-tube nucleic acid testing at highway entrances to the city.

Meanwhile, the city's postal administration launched a pandemic-linked overhaul of the mail and courier businesses on Sunday, targeting courier staff who had poor COVID-19 prevention awareness and companies with inadequate protective measures.

Some courier firms have been ordered to rectify and enhance personal protection of their staff, site management, and disinfection of mails and parcels, according to the administration.

Medium-risk areas in Shanghai at present