BEIJING, Oct. 25 (Xinhua) -- China's National Health Commission on Sunday sent a working group to northwest China's Xinjiang Uygur Autonomous Region to oversee COVID-19 epidemic-control work.

Xinjiang reported one asymptomatic COVID-19 case on Saturday, according to local health authorities.

The patient, a 17-year-old female villager from Kashgar Prefecture, has been placed under quarantine for medical observation at a designated hospital in Kashgar.

All the patient's close contacts have been quarantined for medical observation and nucleic acid testing.

The local epidemic prevention and control headquarters has started an epidemiological investigation into the case.