As Chinese regions tackle the nation's latest COVID-19 epidemic, authorities have requested strengthening supervision at ports of entry and stepping up vigilance and preparedness for the coming winter.

Mi Feng, a spokesman for the National Health Commission, said during a briefing on Oct 30 that as of Oct 29, 14 provincial-level regions had reported locally transmitted positive cases in the past 14 days.

The most concerning cluster of infections is now concentrated in Heihe, a city in Heilongjiang province that borders Russia. The province reported 19 new confirmed infections on Oct 30, including 18 in Heihe and one in the provincial capital Harbin.

In total, China reported 48 domestic confirmed infections on Oct 30, down from a recent high of 59 recorded on Oct 29, commission data shows. It also reported 23 imported cases.

"The virus has circulated in local communities and risks spreading to other regions," said Wu Liangyou, deputy director of the commission's disease prevention and control bureau.

He added that the latest outbreak in Heilongjiang is not linked to infection clusters emerging from Ejine Banner, a county-level port area in the Inner Mongolia autonomous region.

Though both outbreaks were found to be triggered by imported infections, Wu said the sources of imported cases are different based on results from epidemiological investigations and genome sequencing.

He added that in Ejine, the risk of the virus spreading farther has been effectively reined in, and other provinces seeing linked infections have also brought the virus under control.

The Ejine government said on Oct 31 that about 9,000 tourists trapped due to the outbreak had been relocated to low-risk areas, and over 300 stranded travelers still remained in the banner.

Starting from Oct 31, free accommodation will be provided for remaining tourists, it said, adding that the county is at a critical late stage in its efforts to prevail over the virus.

Wu said, "the latest infections have revealed the laxity, ill preparedness for the virus and poor implementation of control and prevention measures by some local governments."

As the weather gets colder and the epidemic situations in some neighboring countries worsen, Wu has urged port regions to ramp up screenings and management of high-risk groups, intensify monitoring of potential new outbreaks and take resolute action to curb new flare-ups.

Li Zhengliang, deputy director of the General Administration of Customs' department of health quarantine, said preventing imported infections remains a key task this winter and spring.

Land ports are required to upgrade and tailor their emergency plans to local circumstances, and antivirus supplies designated for northern regions will be strengthened, he added.

To prevent the virus from being transmitted via cold imports, Li said the administration has halted imports from 154 foreign cold chain manufacturers that are seeing infections among their own employees, with 134 of them voluntarily implementing suspensions.

Meanwhile, China has administered more than 2.26 billion COVID-19 vaccine doses and has fully vaccinated 1.07 billion people as of Friday, according to the commission.

Wu, from the commission, said on Oct 30 that three domestic COVID-19 vaccines have been cleared for emergency use in children aged 3 to 11, further expanding its immunization campaign.

The country aims to vaccinate all eligible children by year's end. As of Oct 29, 3.53 million doses had been delivered to the age group, Wu said.