Mumbai recorded 1,167 new COVID- 19 cases, the highest daily spike in about four months, on Wednesday, the Brihanmumbai Municipal Corporation (BMC) said.
The tally of cases in the country's financial capital thus rose to 3,21,698, while the death toll reached 11,453 with four new fatalities.
On Tuesday, the city had reported 643 new cases and three fatalities.
On October 28, Mumbai had witnessed 1,345 new cases, after which the numbers had gradually fallen.
Wednesday was also the first time this year when new cases were in four digits. Earlier, the city had reported 1,074 cases on December 27, 2020, after which the daily increase had been in three digits and come down to around 300.
But both Mumbai and rest of Maharashtra have seen a spike in cases since the second week of February.
As many as 376 patients recovered in the city on Wednesday, taking the total of recoveries to 3,01,057, while the number of active patients also increased to 8,320 from 7,536 the day before.
The average growth rate of COVID-19 cases in the city went up to 0.24 per cent from 0.17 per cent on Tuesday, whilethe average doubling rate of cases went down to 294 days from 417 days.
The number of tests carried out so far reached 31,85,334 with 21,123 samples being tested since Tuesday evening.
The civic body, with the help of police and railway authorities, has launched a massive campaign to take action against the people roaming around without wearing masks.
On Tuesday, action was taken against over 22,000 persons for not wearing masks.
Meanwhile, 9,830 persons -- 4,565 healthcare workers and 5,265 front-line workers -- were administered COVID-19 vaccines at 34 centers in Mumbai on Wednesday, taking the total number of people who have got the jab to 1,99,912, officials said.
Of 9,830 people, 3,369 were administered a second dose, taking the number of people who have been given a second shot of the vaccine to 13,754.