Residents walks to receive nucleic acid test in Tiexi District of Shenyang, northeast China's Liaoning Province, Jan. 11, 2021. Shenyang is conducting a third round of nucleic acid tests for all residents in Tiexi, Huanggu and Yuhong districts, starting Monday. (Xinhua/Yang Qing)

A community volunteer works at a nucleic acid test site in Tiexi District of Shenyang, northeast China's Liaoning Province, Jan. 11, 2021. Shenyang is conducting a third round of nucleic acid tests for all residents in Tiexi, Huanggu and Yuhong districts, starting Monday. (Photos: Xinhua)

A medical worker collects a swab sample from a resident at a nucleic acid test site in Tiexi District of Shenyang, northeast China's Liaoning Province, Jan. 11, 2021. Shenyang is conducting a third round of nucleic acid tests for all residents in Tiexi, Huanggu and Yuhong districts, starting Monday.

Shenyang conducts 3rd round of nucleic acid tests for all residents in 3 districts.

Residents wait in line for nucleic acid tests in Huanggu District of Shenyang, northeast China's Liaoning Province, Jan. 11, 2021. Shenyang is conducting a third round of nucleic acid tests for all residents in Tiexi, Huanggu and Yuhong districts, starting Monday.