China is battling flare-ups of the coronavirus on its mainland for the first time in weeks. Four new cases were reported on Tuesday, all in the north-eastern province of Liaoning. Overall, more than 30 cases have been detected in two provinces in recent days. Many are linked to a photography studio in the city of Yingkou in Liaoning. The authorities are working to curb the outbreak through mass testing and vaccinations. CGTN's You Yang has more.