China saw its first omicron cases in the community, igniting a mass testing blitz in the northern city of Tianjin as the country strives to maintain its zero-tolerance approach to COVID-19 in the face of more transmissible variants.

The two cases in the port city were confirmed as being omicron by the Chinese Center for Disease Control and Prevention, after its local branch completed the genome sequencing, CCTV reported. The infections were from the same transmission chain but officials have yet to establish if the strain is the same as imported omicron cases reported earlier in Tianjin, according to the report.

China’s commitment to its "COVID zero" policy has seen it restrict movements and implement mass testing and other measures in cities spread across the country. Further outbreaks raise the risk of new lockdown measures that could disrupt production and shipping in an economy already battling weak consumption and a property market slump.