The investigating teams had found a 3-kg cylinder containing trinitrotoluene (TNT) and ammonium nitrate from under the sacred Bodh Gaya tree, which was not damaged during the blasts. The explosives used were similar to that of the bombs used by Maoists.
Until Bhatkal had confessed about his involvement, the NIA was probing into three possibilities-Naxal involvement, international infiltration and local communal issues. In this regard, the agency had also held 100 foreign national students in Magadh University, especially after the sketches of the blast suspects were released.
Bhatkal further confessed that he had supplied explosive materials to a person to plant in various parts of the country. "During his interrogation, Bhatkal revealed that Pakistan's intelligence agency has been working on a multipronged strategy to spread terror in India. For this, they are trying to rope in the Naxals as well," said an NIA official.