All 17 of the the locally transmitted new cases were reported in the capital, according to the latest figures from the national health authorities.
Four imported cases were also reported in Guangdong, Gansu, and Shanghai.
The uptick in new cases in Beijing goes against predictions by National Health Commission expert Wu Hao.
After just nine new cases were reported on Monday he said that the situation had reached a “calm” and that new cases would either remain in the single digits or precipitously drop this week.
A total of 299 new COVID-19 cases have been confirmed in Beijing since a local cluster was traced back to the sprawling Xinfadi wholesale market in the city’s south-western Fengtai district on June 11.
Since then the capital has taken drastic steps to contain the outbreak, conducting mass testing, closing schools, putting neighbourhoods on lockdown, and banning all unnecessary travel.
On Friday the Chinese Center for Disease Control and Prevention (CCDC) confirmed that the strain of the virus sweeping through Beijing is not the same as the one found in the initial epicentre of the pandemic, Wuhan, in late 2019.
The CCDC also ruled out the possibility of zoonotic transmission like in Wuhan, where the virus first jumped from an animal host into humans at the Huanan Seafood Wholesale Market.
According to the CCDC’s top epidemiologist Wu Zunyou, the Beijing strain is similar to Europe’s, but was not necessarily transmitted directly from European countries.