The government of Hong Kong Special Administrative Region (HKSAR) made a "restriction-testing declaration" effective from 19:00 p.m. Tuesday on Kowloon's Sham Shui Po, Jordan, and New Territories' Tin Shui Wai areas, by which people within the specified "restricted areas" were required to stay in their premises and undergo compulsory testing for COVID-19.

The government had found that the effluent discharged from buildings in the three districts tested positive for novel coronavirus, which suspected that there are COVID-19 cases in the areas, said in a statement.

It is necessary to make a restriction and testing declaration in the "restricted areas" to confirm that all people in the areas have undergone mandatory testing and to cut off the chain of transmission, the statement added.