The Chinese mainland on Sunday reported 21 new locally transmitted COVID-19 cases, the National Health Commission said in its daily report on Monday.
Of the new local cases, 20 were reported in Inner Mongolia and one in Yunnan.
China's National Health Commission (NHC) and the Chinese Center for Disease Control and Prevention (CDC) have dispatched a work group to Manzhouli, a border city in North China's Inner Mongolia Autonomous Region, to address the latest round of COVID-19 flare-ups.
The work group was dispatched on Sunday, after the city reported 19 confirmed cases of COVID-19 and one silent carrier from midnight Saturday to 4 pm on Sunday, according to the NHC's statement.
There are no test results yet to show which strain caused these infections.
Manzhouli is a city bordering Mongolia and Russia, with many China-Europe freight trains passing through every year, contributing to the global economic revival and supply chain stability amid the pandemic.