The deceased have been identified as Ahad Mati (19) and Mohammed Fardeen Nagori (17), residents of Agarwal Compound in suburban Jogeshwari, a civic official said.
Four of their companions had been rescued.
MCGM has formed six teams to patrol the sea shore during times of high tide, each team of 15 members, drawn from fire brigade, National Disaster Response Force and lifeguards,
The teams have been deployed in areas like Girgaon, Dadar, Juhu, Versova, Aksa beach, Gorai beach and Chowpatty beach, where large crowds frequent during the monsoon.