The city reported another 31 cases on Wednesday, bringing the total to 137 in the past week.
Before the recent spike, the Chinese capital had gone 57 days without a locally-transmitted case.
The outbreak is believed to have started in the massive Xinfandi food market that supplies 80% of the city's meat and vegetables.
At least 27 neighbourhoods have been classed as medium risk and one neighbourhood, near the market, is high risk.
People in medium or high-risk areas cannot leave the city. People in low-risk areas can leave, but need to test negative first.