A total of 138 asymptomatic cases of the novel coronavirus were reported in the Kashgar Prefecture in northwest China's Xinjiang Uygur Autonomous Region, according to the local health authority.

The city reported the first asymptomatic case, a 17-year-old female villager, on Saturday. Another 137 asymptomatic cases were reported as of 2:00 p.m. on Sunday.

All 137 asymptomatic cases were connected to a factory where the first asymptomatic patient's parents worked.

After the first new asymptomatic case of COVID-19 was detected, the Xinjiang authorities have sent over 600 workers to Kashgar to help conduct nucleic acid tests for residents in the region.

Over 4,740,000 residents need to be tested in the region, authorities said, adding that as of 2:00 p.m. on Sunday, more than 2,830,000 people had been swabbed for the novel coronavirus test.

A level-I emergency response has been activated due to the new coronavirus cases, the local authority said. Four towns in Kashgar will be classified as high-risk areas starting from Monday, following the surge in asymptomatic COVID-19 cases,  local authorities said.