A medical worker wearing protective suit works at a COVID-19 testing site in Hedong District in north China's Tianjin, Jan. 20, 2022.
The city launched its fourth citywide nucleic acid testing at 6 a.m. Thursday, aiming to curb the further spread of the virus. (Xinhua/Sun Fanyue)
A medical worker takes a swab sample from a resident for nucleic acid test at a COVID-19 testing site in a residential community of Nankai District in north China's Tianjin, Jan. 20, 2022.
The city launched its fourth citywide nucleic acid testing at 6 a.m. Thursday, aiming to curb the further spread of the virus. (Xinhua/Zhao Zishuo)
A medical worker takes a swab sample from a resident for nucleic acid test at a COVID-19 testing site in a residential community of Nankai District in north China's Tianjin, Jan. 20, 2022.
The city launched its fourth citywide nucleic acid testing at 6 a.m. Thursday, aiming to curb the further spread of the virus. (Xinhua/Zhao Zishuo)
Residents and volunteers queue up for nucleic acid tests at a residential community in Nankai District of north China's Tianjin, Jan. 20, 2022.
The city launched its fourth citywide nucleic acid testing at 6 a.m. Thursday, aiming to curb the further spread of the virus. (Xinhua/Zhao Zishuo)
A medical worker takes a swab sample from a resident for nucleic acid test at a COVID-19 testing site in Hedong District in north China's Tianjin, Jan. 20, 2022.
The city launched its fourth citywide nucleic acid testing at 6 a.m. Thursday, aiming to curb the further spread of the virus. (Xinhua/Sun Fanyue)
A medical worker takes a swab sample from a resident for nucleic acid test at a COVID-19 testing site in a residential community of Nankai District in north China's Tianjin, Jan. 20, 2022.
The city launched its fourth citywide nucleic acid testing at 6 a.m. Thursday, aiming to curb the further spread of the virus. (Xinhua/Zhao Zishuo)
Medical workers head for a COVID-19 testing site at dawn in north China's Tianjin, Jan. 20, 2022.
The city launched its fourth citywide nucleic acid testing at 6 a.m. Thursday, aiming to curb the further spread of the virus. (Xinhua/Sun Fanyue)
A medical worker takes a swab sample from a resident for nucleic acid test at a COVID-19 testing site in Hedong District in north China's Tianjin, Jan. 20, 2022.
The city launched its fourth citywide nucleic acid testing at 6 a.m. Thursday, aiming to curb the further spread of the virus. (Xinhua/Zhao Zishuo)
A resident arrives to receive nucleic acid test at a COVID-19 testing site in a residential community of Nankai District in north China's Tianjin, Jan. 20, 2022.
The city launched its fourth citywide nucleic acid testing at 6 a.m. Thursday, aiming to curb the further spread of the virus. (Xinhua/Zhao Zishuo)
Staff members prepare medical materials for nucleic acid tests at a COVID-19 testing site in a residential community of Nankai District in north China's Tianjin, Jan. 20, 2022.
The city launched its fourth citywide nucleic acid testing at 6 a.m. Thursday, aiming to curb the further spread of the virus. (Xinhua/Zhao Zishuo)