BEIJING (BLOOMBERG) - A county neighbouring Beijing has been locked down after finding one preliminary positive Covid-19 case, the second time this week an area close to the capital has used the measure in a reflection of mounting efforts to curb transmission.

Xianghe, in the northern province of Hebei, issued a stay-at-home order to its 384,000 residents from Friday (Aug 26) and suspended all non-essential business and public transport.

People can go out only for urgent medical services or to take part in mass testing.

The county is about 30 miles (48km) south-east of Beijing and residents often commute to the city for work.

It follows a snap lockdown in Zhuozhou, which borders the capital to the south-west, on Tuesday after finding eight Covid-19 cases.

The swift moves indicate how determined the authorities are to keep the virus from spreading to Beijing, which has managed to keep its daily case tally below two digits for more than two months.

China's political centre has deployed strict rules to keep the virus at bay, requiring residents to get a polymerase chain reaction test every three days in order to take transport and enter most venues, and ban entry to travellers coming from places that have had Covid-19.

Even with Beijing averting a widespread flare-up, the lockdowns of commuter areas risk disruptions to the capital as many workers will now be stuck at home.

Xianghe and Zhuozhou have not said when their restrictions will lift.

A substantial virus incursion into Beijing would be a major test for China's zero-Covid strategy, and risks occurring in the run up to a political meeting later this year when President Xi Jinping is expected to secure a precedent-breaking third term as leader.

China reported 1,501 local cases for Thursday, down from a peak of more than 3,400 last week, as outbreaks in tourism destinations such as Hainan and Xinjiang ebb.