The Xinjiang Uygur autonomous region reported five new confirmed cases and 19 new asymptomatic cases of COVID-19 between 12 am and 5 pm on Tuesday, a local health official said.

All the confirmed cases were from the group of asymptomatic patients diagnosed since Saturday, some of whom have begun to show symptoms, said the official, Li Linyu, Party secretary of the Kashgar health commission. Asymptomatic cases are placed in a different category from confirmed cases, in which symptoms are present.

All the new cases were identified in Shufu county, Kashgar prefecture, Li said at a news conference. As of 5 pm on Tuesday, the region had reported a total of 178 asymptomatic cases as well as the five confirmed cases, Li said.

Kashgar had completed nucleic acid tests on its more than 4.74 million residents by Tuesday afternoon, and all but 183 people had tested negative, he said.

Kashgar initiated free nucleic acid tests for all residents after a 17-year-old female villager from Shufu was confirmed as an asymptomatic carrier of the virus on Saturday.

The reason most of the reported cases have been asymptomatic carriers is that they are still in the early stages of infection, though there may be more confirmed cases as the infection progresses, Li said.

He said experts from the county to the national level have stepped up efforts to perform epidemiological investigations on all reported cases, close contacts and people who have traveled to high-risk areas since Oct 17.

Genome sequencing of the viruses extracted from the cluster of cases in Kashgar has shown that the new cases have no connection with the outbreak in Urumqi in July, Li added.

Asat Ulayim, a Kashgar government official, said all close contacts of the reported cases have been quarantined for medical observation.

The quarantine centers are sterilized and ventilated every day, and they are equipped with daily necessities, internet connections and televisions. People under quarantine are also provided with free meals, he added.