As COVID-19 continues to spread in the city's posh localities, the number of sealed residential buildings has doubled in a little over 30 days, while Containment Zones in slum pockets have increased slightly. The number of sealed buildings in the city rose to 5,646 on June 28 from 2,533 on May 23, according to the data provided by the BMC.

The number of cluster cases in high-rises has become a challenge for the BMC.