Among those who tested positive are a former MP and a former state minister.
The official added that the number of cases in Thane municipal limits crossed the 5,000-mark.
The death toll in the district was inching towards the 500-mark, with the current count being 493 after 19 people succumbed to the infection on Saturday, he said.
"Of the 775 cases, Navi Mumbai accounted for 191, Thane city 179, Kalyan 160 and Mira Bhayander 106. The number of cases in Thane city is now 5,005, while it is 3,734 in Navi Mumbai, 2,071 in Kalyan and 1,514 in Mira Bhayander," he informed.
Neighbouring Palghar has 1,858 cases, which includes 61 deaths so far. COR BNM BNM