Xi'an, Shaanxi province, reported one confirmed case and 10 asymptomatic carriers of COVID-19 on Tuesday, the provincial Health Commission said on Wednesday.

Between Saturday and Tuesday, the city reported 11 confirmed cases and 18 asymptomatic carriers, most of which were related to a recycling resource trade market.

Gene sequencing show that the Omicron subvariant BA.5.2 is to blame for this cluster of cases, which is more contagious than the previous strain, said Ma Chaofeng, deputy director of Xi'an Center for Disease Control and Prevention.

The government will strengthen efforts to trace the sources of infection and arrange resources for testing, said Liu Guozhong, Party secretary of Shaanxi. The public's daily needs need to be guaranteed, he added.

A seven-day temporary control measure was imposed starting on Wednesday in Xi'an, a city of 13 million people.

During the period, dine-in services are suspended and entertainment venues are closed. Supermarkets, hospitals and convenience stores will be open as usual.