BEIJING -- The current COVID-19 infections in China were caused by unrelated imported cases, said the National Health Commission (NHC) on Nov 6.

The result was indicated by viral genome sequencing and epidemiological investigations, Wu Liangyou, an official with the NHC, said at a press conference.

Multiple transmission chains have been identified in this round of COVID-19 infections. Confirmed cases have been reported in 20 provinces by Nov 5.