Health officials took no chances on Wednesday, sealing off the capital of the industrial Hebei province and ordering a mass testing drive.
Travel restrictions were put in place in the remainder of the region, which encircles China's capital Beijing and is home to some 76 million people.
By Saturday, Mayor Ma Yujun told a news conference that it had taken just three days to complete the first round of mass testing in Shijiazhuang, with 354 people found positive for the virus. A second round of testing is due to begin soon, he added.
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Yan Xixin, a critical care director at the Second Hospital of Hebei Medical University, told the same news conference, "the risk of having more infections is still there."
This hard-and-fast approach is being echoed elsewhere in the Asia-Pacific region to fend off coronavirus flare-ups — including in Japan, Thailand and Australia — making measures to curb the virus spread in Europe and the United States appear almost sluggish.
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