(Bloomberg) -- Covid-19 cases in Shanghai continued to climb as parts of China’s financial hub face more rounds of mass testing, with new sub-variants providing a constant challenge to the country’s zero-tolerance approach to the virus.

The city recorded 69 new infections for Sunday, the most since late May and up from 57 the day before. Cases have increased abruptly after a period of little to no trace of the virus, where officials declared victory over Covid and praised their handling of a crisis that left China’s most global city locked down for two months in May and June. 

Shanghai found its first case of the more contagious BA.5 sub-strain of the omicron variant Friday, triggering two rounds of mass testing between Tuesday and Thursday in nine districts, plus other areas where cases have been found, a health official said Sunday. 

What We Know About the Omicron Clan of Virus Variants: QuickTake

Elsewhere, Shandong province reported 80 local cases and Beijing announced one infection.

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