Authorities said on Sunday that environmental samples in four places in Shunyi District of Beijing came back positive for COVID-19. 

A total of 5,365 environmental samples were collected in the district, said authorities, adding that as of 2 p.m. on Sunday, a total of 2,035 close contacts of confirmed COVID-19 cases were transferred to a designated quarantine facility for medical observation.

As of Saturday, 73,537 doses of COVID-19 vaccine were injected in Beijing. No serious adverse reactions have been reported.