The four were later produced before a court which, remanded them to police custody till October 13, police sources said. They were identified as Mohammed Shafi, Shaikh Mohammed, Mohammed Majid and Abdul Vahiuddin.
Although police did not disclose the role played by them in the blasts, sources said it was suspected that they were involved in the conspiracy. One of them is from Kolkata while the rest, hail from Mumbai.
Most of those arrested in the case are alleged LeT operatives and nine of them were trained by Azam Cheema in Pakistans Bahawalpur district.
Four of the arrested Kamal Ahmed, Tanvir Ansari, Ehtesham Siddiqui and Faisal Sheikh have been booked under Maharashtra Control of Organised Crime Act (MCOCA) and subjected to narco-analysis tests in which, they allegedly confessed to their involvement in the blasts.