A staff member of epidemic prevention and control stands guard at the entrance of a residential compound in Huanggu District, Shenyang of northeast China's Liaoning Province, Jan. 4, 2021. A total of 16 areas have been identified as medium-risk zones for COVID-19 in Shenyang, with prevention and control measures in place, local health authorities told a press briefing here on Monday. (Xinhua/Yao Jianfeng)