Hours after two hospitals in Shanghai were sealed off due to possible coronavirus infections, the city’s health authorities confirmed three local cases on Thursday.

During an afternoon press conference, Wu Jinglei, director of the Shanghai Health Commission, said the new infections were reported at the Fudan University Shanghai Cancer Center, in the city’s downtown Xuhui District, and Renji Hospital, located in the central Huangpu District. He said the hospital had detected a “suspected” patient during a routine test Wednesday evening.

That patient has been identified as a 56-year-old man who worked at the cancer center, while the two others were his close contacts, according to Wu.

The man’s residential community in the city’s Huangpu District has now been categorized as a medium-risk area, a district official said, and all of its residents will be quarantined in designated hotels and tested for the virus.

As of Thursday afternoon, some 6,000 medical workers at the cancer center had tested negative for the virus, according to Zhang Wenhong, director of the infectious diseases department at Shanghai’s Huashan Hospital. Local media reported that workers at all of the city’s hospitals will also be tested as soon as possible.

Both medical facilities have temporarily suspended their outpatient services, with inpatient services unaffected, Wu said. Patients requiring special medical attention will be transferred to separate facilities if needed.

Shanghai had not reported any local coronavirus infections since seven such cases were identified in the Pudong New Area in November. Those infections were traced to cargo workers at Shanghai Pudong International Airport, as well as their close contacts.

Reports of the new cases come just a day after Shanghai kicked off a mass vaccination drive. As of Tuesday, more than 800,000 people in the city had received at least one of two injections of a domestically made COVID-19 vaccine.

As other countries have struggled to cope with mounting infections, China has largely managed to contain the spread of the novel coronavirus and reopen its economy. However, recent weeks have seen a record number of domestic cases, highlighting the difficulty of containing the pandemic entirely.

On Wednesday, China reported 144 new local COVID-19 cases, matching the country’s highest daily caseload since March 1, according to health authorities. Most of the recent outbreaks have been in the country’s north, including the provinces of Hebei and Heilongjiang, as well as Beijing.

In the wake of the Shanghai cases, officials are urging residents to refrain from traveling during the upcoming Lunar New Year holiday to prevent additional outbreaks. On Wednesday, China’s National Health Commission said migrant workers returning home between Jan. 28 and March 8 are encouraged to get tested for COVID-19 prior to traveling, and must submit to a 14-day health monitoring period and compulsory tests upon arriving in their hometowns.

Editor: Bibek Bhandari.

(Header image: Medical workers speak to an elderly resident near Renji Hospital in Shanghai, Jan. 21, 2021. People Visual)