With the addition of 297 coronavirus positive cases, the infection count in Thane district of Maharashtra mounted to 5,57,436, an official said on Friday.
These new cases were reported on Thursday, he said.
As the virus claimed the lives of four persons during the day, the death toll in the district rose to 11,390.
Thane's COVID-19 mortality rate is 2.04 per cent, he added.
In neighboring Palghar district, the infection tally has gone up to 1,35,588, while the death toll is 3,273, another official said.