Beijing officials sealed off several residential communities in the city’s northern district on Sunday after two cases of Covid-19 were found.

The Anzhenli neighbourhood in the Chaoyang district of the capital was closed off on Saturday, and residents will not be allowed to leave their compound.

Beijing is on high alert as it prepares to host the Olympic Games, which open on Friday.

While the cases are low compared with other countries in the region, China has doubled down on its “zero-tolerance” policy, which includes breaking the chain of transmission as soon as it is found.

The city is also setting up 19 points in the area to test residents every day until Friday, officials said at a briefing on the pandemic, according to state-backed Beijing News.

The Chinese capital reported a total of 12 cases of Covid-19 between 4pm on Saturday and 4pm on Sunday, said Pang Xinghuo, the vice head of the Beijing Centre for Disease Prevention and Control.

All of those cases involved people who were already under some kind of pandemic control measures.

The city carried out multiple rounds of testing for millions of residents over the past week in Fengtai district, where some residential compounds were locked down.