People wearing face masks to help curb the spread of the coronavirus walk by office buildings during the morning rush hour in Beijing, capital of China, on Dec 1, 2020. (ANDY WONG / AP)

BEIJING/HOHHOT/CHONGQING - China's National Health Commission said Tuesday that it received reports of 12 newly confirmed COVID-19 cases on the Chinese mainland Monday, including four domestically transmitted cases and eight imported ones.

All the local cases were reported in the city of Manzhouli in the Inner Mongolia autonomous region, according to the commission and local health authorities.

Among them, three patients were re-categorized from previously reported asymptomatic carriers, the local health authorities said, adding that one new asymptomatic case was also reported.

Among the eight new imported cases posted on the mainland, two each were reported in Shanghai, Fujian and Sichuan while Beijing and Shaanxi saw one case each, the National Health Commission said

Meanwhile, of the new imported cases posted on the mainland, two each were reported in Shanghai, Fujian and Sichuan while Beijing and Shaanxi saw one case each, the commission said.

There were no newly reported suspected cases or deaths related to COVID-19, the commission said.

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Twelve more patients were discharged from hospitals after recovery, it said, adding that there were 277 patients still receiving treatment, of whom eight were in severe condition.

By the end of Monday, a total of 3,866 imported cases have been reported on the mainland. Among them, 3,621 have been discharged from hospitals while 245 remained hospitalized. No deaths have been reported among the imported cases.

Overall, the mainland has recorded a total of 86,542 confirmed cases, inclduing 81,631 recoveries and 4,634 deaths, according to the commission.

There were six suspected cases on the mainland as of Monday, and 7,147 close contacts remained under medical observation.

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Monday also saw five newly reported asymptomatic cases, four of whom arrived from outside the mainland. On the same day, five asymptomatic cases were re-categorized as confirmed cases.

A total of 264 asymptomatic cases were under medical observation, including 259 who arrived from outside the mainland, according to the commission.

Meanwhile, all the nucleic acid test results returned negative for the contacts of a traveler from Chongqing who was initially diagnosed as an asymptomatic case upon arriving in the Republic of Korea (ROK), the health authorities of Chongqing said.

The city had traced more than 8,000 people who had contact with the traveler, who is an employee of a local company, or with his close contacts, the local health authorities said. The second nucleic acid test of the traveler in the ROK turned out to be negative, his company said.

By the end of Monday, 6,314 confirmed cases, including 109 deaths, have been reported in Hong Kong Special Administrative Region (SAR), while Macao SAR has recorded 46 confirmed cases and Taiwan has logged 675 cases, including seven deaths.

A total of 5,344 patients in Hong Kong SAR, 46 in Macao SAR 565 in Taiwan have been discharged from hospitals after recovery.