The Maharashtra Anti Terrorism Squad has undertaken massive combing operations across several districts of Maharshtra, Uttar Pradesh and Karnataka.
Gujarat and Madhya Pradesh ATS are also assisting the investigating team in their respective states.
Sources have confirmed to rediff.com that all known Students Islamic Movement of India operatives - acquitted or out on bail are being picked up for questioning. Teams have also started enquiring about the absconding Indian Mujahideen operatives with their respective family members.
ATS officers speaking on condition of anonymity said that as many as 16 SIMI operatives are under the scanner for interrogation to secure any possible leads into the 13/7 serial bombings. One suspect has also been picked up from Buldhana's Undri area.
Even as the ATS is awaiting a detailed forensic report, investigation is gradually picking up momentum. However, sources say, that while questioning of suspects is underway at multiple places, so far nothing concrete has come up.