"It is worth mentioning that Yasin Bhatkal was one of the most important members of IM who was involved in planning and execution of large number of blast cases in which more than 150 people were killed," the NIA said.
It alleged that Bhatkal has very strong "jihadi mindset" and he was involved in identifying, motivating, recruiting and training several youths in causing bomb blasts in the name of jihad.
"He was instrumental in developing bases in Darbhanga, Ranchi, Samstipur, Goa, Mangalore etc he had also received training in Pakistan for 60 days," it said.
Regarding Akhtar, the NIA said he was closely associated with Bhatkal for the past six years in all terror attacks.
"During the course of investigation, the active role of Yasin Bhatkal and Asadullah Akhtar, in the conspiracy and participation in major terrorist attacks at different parts in the country, was revealed," it said.
Regarding Imam and Ahmed, NIA claimed they hailed from Ranchi in Jharkhand and have been named in the charge sheet for their role in the conspiracy to commit terrorist acts by the IM and also for raising funds for the terror organisation.