China is facing challenges dealing with the COVID-19 epidemic as the Omicron variant makes tracking cases or preventing the spread of infection more difficult due to the ease of transmission and higher infectivity.

Since Nov 1, about 253,000 cases have been reported, with an average of roughly 22,200 cases reported daily last week, said Hu Xiang, an official with the National Administration of Disease Prevention and Control, at a news conference in Beijing on Tuesday.

She said that the latest epidemic has expanded due to complicated transmission chains, with some provincial level regions facing the most difficult situations they have dealt with in three years.

Densely populated cities such as Guangzhou, capital of Guangdong province, and southwest Chongqing municipality have been designated as key areas in efforts to contain the epidemic because of their larger populations and the ease of their residents' mobility.

She added that the ease of transmission and higher infectivity of the Omicron variant have made tracking and treating cases more challenging. The problem could lead to a short supply of epidemic control workers and medical resources if cases are found in places where people typically gather, such as factories, hospitals and schools.

"Allowing for the current situation, the central government has sent working teams to help guide local authorities to deal with the epidemic," Hu said. "We will continue to prioritize people's lives and work to prevent inbound cases, epidemic expansion and domestic resurgence by continuing to implement the dynamic zero-COVID policy."

She reminded the public to continue washing their hands, wearing masks and maintaining social distance as the novel coronavirus is transmissible through droplets and close contact.