The order was announced at 4:00 a.m. on Saturday (20:00 GMT on Friday) catching residents by surprise, with many learning of the lockdown while heading out to work, South China Morning Post reported.

About 150 housing blocks of the low-income Jordan neighborhood, where many residents live in subdivided apartments, were cordoned off by police as health care and social workers were mobilized to begin a mass testing drive, according to the newspaper.

COVID-19 cases began a steep climb over the course of the month, centered around the Kowloon district, with over 50 infections reported daily since mid-January. Over 700 people are currently hospitalized, with 34 in critical condition.

Since the beginning of the pandemic, the special administrative region has registered just under 10,000 cases and 168 deaths.