A Lashkar-e-Tayyaba spokesman, Abdullah Ghaznavi, has denied the group was involved.
On Friday, Bombay Police Commissioner A.N. Roy said a man known only as Rahil was being sought in connection with the blasts.
The government's Anti-Terror Squad Thursday night had released photos of two other suspects, Sayyad Zabiuddin and Zulfeqar Fayyaz, the AP reports.
Their nationalities were not given, nor was it clear where the photos of the two young, bearded men originated.
Roy said the two had been on the run since mid-May, when authorities arrested three suspected Muslim insurgents and seized large quantities of arms, ammunition and plastic explosives after a long highway chase in western India's Maharashtra state. Bombay is its capital.