Khorgas, port city in the Ili Kazak Autonomous Prefecture, Northwest China's Xinjiang Uygur Autonomous Region Photo: VCG

Two asymptomatic cases reported on Sunday, in Northwest China's port city of Khorgas, were confirmed to be caused by Omicron variant after gene sequencing, local authorities said on Tuesday, indicating that this outbreak is spreading fast and the source of the infection is still unknown.

The confirmed cases found during a regular screening had no travel history to medium- and high-risk areas, did not receive hospital treatment or touched cold chain foods, and had no contact with staff under high-risk closed-loop management within 14 days before their nucleic acid tests came back positive, according to the authorities at Tuesday's press briefing.

As of Tuesday evening, eight confirmed COVID-19 cases and 24 asymptomatic cases have been reported in Khorgas city, in the Ili Kazak Autonomous Prefecture, Xinjiang Uygur Autonomous Region.

As a major port city, Khorgas, along with other port cities such as Suifenhe, has been at the frontline fending off imported cases of COVID-19 during the past two years. 

The city has implemented measures to encourage residents to stay put for the upcoming Spring Festival holidays and not leave the city unless it is necessary to minimize the risk of contagion.

Five areas in Khorgas city were classified as medium-risk for COVID-19 on Tuesday and have been put under closed-loop management, the authorities said.