(Corrects the number of locally transmitted asymptomatic cases in paragraph 2 to 137, not 138)

SHANGHAI, Oct 26 (Reuters) - China reported 20 new confirmed and 161 new asymptomatic COVID-19 cases on Oct. 25, the national health authority said on Monday, following a surge in symptomless infections in the northwestern Xinjiang region.

The National Health Commission said in a statement that all new confirmed cases were imported infections originating from overseas. Of the 161 new symptomless infections, which China does not classify as confirmed cases, 137 were locally transmitted.

Kashgar in Xinjiang region on Saturday started testing its 4.75 million people after detecting an asymptomatic patient at a garment factory. Another 137 asymptomatic cases have been reported on Oct. 25 due to the tests being conducted.

A total of 85,810 confirmed COVID-19 cases have been reported in mainland China to date, while the death toll remains unchanged at 4,634. (Reporting by Andrew Galbraith and Jing Wang; writing by Se Young Lee; Editing by Kim Coghill)