Beijing reported 51 new locally transmitted confirmed cases and four new asymptomatic carriers between 3 pm on Saturday and 3 pm on Sunday, which means that the city's total infection number has hit 350 since April 22 and involves 14 districts, said the Beijing CDC on Sunday.

The Beijing CDC has conducted the gene sequencing of the 51 new cases and the results showed that virus was Omicron variant and the source was the recent clusters found in Chaoyang district, said Pang Xinghuo, deputy director of the Beijing CDC, at a news conference on Sunday.

"By now, the center has completed the gene sequencing of 158 samples from the local patients during the latest outbreak," she said. "The results showed that the infections involved the Omicron variant and are part of two different transmission chains.

"The gene sequencing is identical to the recent infection clusters outside Beijing, which spilled out to other parts of the country as well," she added.

Among the total 350 infections, Chaoyang district registered 143 cases, followed by Fangshan district, which reported 86 cases by Sunday since April 22, according to Pang.

Due to the increasing number of COVID-19 cases in Chaoyang, two more residential communities in the district were designated as high-risk areas starting on Sunday.

As of Sunday afternoon, Beijing had seven high-risk areas for COVID-19 and 28 medium-risk areas.