A link has been found between three of the recent COVID-19 cases in Beijing with the virus outbreak in east China's Nanjing, Beijing's health authorities said on Tuesday.

They said genome sequencing of samples from the three cases showed a high degree of homology with the cases reported in Nanjing.

As of Monday, Beijing had logged nine local transmissions of the virus related to cases outside the capital since July 28.

China has stepped up prevention and control measures to snuff out a wide-spanning outbreak from an international airport in Nanjing since July 20.