Not all cities are required to ensure nucleic acid testing is available within a 15-minute walk and not everyone should get tested every 48 hours, a senior health official said on Monday.

Guo Yanhong, an official with the National Health Commission, said only provincial capitals and cities with more than 10 million people should offer tests within a 15-minute walk and the frequency of the tests depends on the severity of local outbreaks.

Early and regular nucleic acid testing is key to finding potential sources of transmission of the highly infectious Omicron variant, she said at a news conference.

Cities including Hangzhou, Shanghai, Shenzhen, Dalian and Hefei have opened more testing sites based on the local situation for the convenience of residents, she said.

The prices of testing have been lowered and relevant departments under the State Council are encouraging local authorities to further lower test costs and prices, she added.