BEIJING - China has partially sealed off the city of Shijiazhuang in northern Hebei province, after the province reported 63 confirmed cases of Covid-19 on Tuesday (Jan 5), sparking fear that this could herald a new wave of infections in the country.
The province, which neighbours the Chinese capital, declared it was going into "war-time mode" after reporting a spike in cases on Tuesday night.
Provincial authorities had reported 20 new confirmed cases, as well as 43 asymptomatic ones - virtually all from the provincial capital of Shijiazhuang, about 300km from Beijing.
China does not include asymptomatic cases in its official tally, but the combined number of cases, both symptomatic and asymptomatic, on Tuesday, marks the single largest daily rise in local cases since last October.
A number of the cases had attended various wedding banquets or celebrations in the city in the last few days.
A major industrial hub known for its poor air quality, the city of 11 million people kicked off mass testing on Wednesday, in what has become protocol when such sporadic clusters emerge.
But there are signs that this could mark the start of a more serious outbreak - expert teams from Beijing have been sent to the province, and movement curbs have been put in place as the authorities implement what seems to be a partial lockdown.
Inter-city buses, as well as many inbound and outbound flights to Shijiazhuang have been cancelled.
Sale of train tickets to Beijing was also suspended on Wednesday.
Traffic on 10 highways connecting Shijiazhuang to Beijing and other provinces have also been restricted, with traffic police urging vehicles on both sides to return to where they came from.
Shijiazhuang resident Ma Yingnan told The Straits Times that people in the city were mostly holed up at home, waiting to get notice to go for mass nucleic acid tests.
"There are not a lot of people on the streets. People are worried but what can you do? We are just waiting to be notified (to get tested)," said the 30-year-old.
Chinese health experts expect the numbers of infected cases to continue to climb.
In a meeting on Tuesday with provincial authorities, National Health Commission director Ma Xiaowei said the current epidemic situation in Hebei was "severe" and still developing.
Mr Feng Zijian, deputy director of China Centre for Disease Control and Prevention, said the strain of the virus spreading in Hebei was not local to China and was possibly linked to strains in Europe, state broadcaster CCTV reported on Tuesday.
He added that cases would likely continue to climb and that the virus had been spreading undetected for some time.
The current cluster in Hebei first emerged on Sunday, when one case was reported in Xingtai city, just adjacent to Shijiazhuang.
Then, officials uncovered a raft of cases in days following that. Before this outbreak, the last local transmissions in Hebei had occurred in June.
The situation in Hebei has caused jitters in the Chinese capital, which adjoins the province and is also battling an outbreak of its own.
City officials said on Tuesday that international travellers arriving in Beijing must quarantine for 21 days, seven more than previously required, after cases in the capital tested positive following their release from quarantine.
While the first 14 days must be spent at a government-designated facility, the additional week can be completed at home with approval from local authorities.
Additional tests - on stool and environmental samples - will also be conducted.
On Wednesday, Beijing officials also urged people who have travelled to Shijiazhuang or Xingtai recently to report their travel history to their local communities.
Dr Jin Dong-Yan, a virology professor at the University of Hong Kong, said it was "worrying" that the virus had been spreading unnoticed for awhile, and current cases could be the "tip of the iceberg".
"The problem in China is that mass gatherings, wedding ceremonies, and events like these have already been resumed. It's almost back to pre-Covid-19 times, so if cases go undetected there can be superspreader events," he said.
With the coming Chinese New Year travel rush coming up, Beijing is racing to head off any such possibility, and is reportedly aiming to vaccinate 50 million people before the holiday next month.
Various Chinese cities including Beijing and Shanghai are vaccinating thousands each day after the country's drug regulator gave conditional approval to a vaccine by Sinopharm last week.
Officials said last Thursday that more than three million people have been vaccinated since Dec 15.