BEIJING: Beijing city officials on Sunday said all two million residents of a neighbourhood where a small cluster of coronavirus cases was detected will be tested, less than two weeks before the start of the Winter Olympics.

China's cases constitute a tiny fraction of the massive surge in countries around the globe, with the highly contagious Omicron variant driving a fresh spike in infections.

Still, multiple small outbreaks around China -- including in Beijing -- have tested its strict "zero Covid" policy, which authorities have pursued even as the rest of the world has gradually reopened.

Local authorities have identified Fengtai district in southern Beijing as the epicentre of a cluster, with the number of cases in the capital totalling 43.

All two million of the area's residents will be tested for the virus on Sunday, officials said, and people from high-risk areas are banned from leaving the city.

"We must make every effort to stop the spread as quickly as possible by taking firm, strict and decisive measures," Xu Hejian, spokesman for the Beijing municipal government, said at a briefing.

Fengtai is about 20 kilometres (12 miles) from the Winter Olympics freestyle skiing and snowboarding venue.

With the Beijing Games starting on February 4, international delegates, media personnel, and some athletes have already begun arriving.

In an effort to thwart the coronavirus, China is sealing the Olympics inside a tightly controlled bubble cocooning thousands of people and stretching nearly 200 kilometres (120 miles).

The testing announcement came days after China's postal service ordered workers to disinfect international deliveries after authorities claimed mail could be the source of recent coronavirus cases.

Both the World Health Organization and the US Centers for Disease Control have said the risk of being infected from contaminated surfaces is low.