File photo: China Daily

The three new asymptomatic COVID-19 patients who were reported in the Alashankou Port in Northwest China's Xinjiang Uygur autonomous region were infected with the Delta variant of novel coronavirus from overseas, the regional center for disease control and prevention acknowledged Wednesday.

The Chinese Center for Disease Control and Prevention has generated information from the genomic sequence of the virus the cases are carrying using laboratory methods of next-generation sequencing. The result shows they caught the Delta variant, indicating the virus was imported from abroad.