Xian, the capital of China’s northwestern Shaanxi province, went into lockdown on December 23, 2021, after more than 230 new Covid-19 cases were detected. Early reports say that none of the positive cases showed the new Omicron variant, but the cluster has spread to four cities, including Beijing, before the city was shut down. Health officials began citywide testing of its 13 million residents as the city’s streets and airports were left deserted.