Who carried out the series of eight blasts in Bangalore on July 25 that left one person dead is a question that is still daunting investigators in Karnataka, despite the arrest of an alleged SIMI activist.

The direct involvement of Riyaz Bhatkal, and the Indian Mujahideen outfit he founded, is being ruled out with a key aide telling interrogators that Bhatkal was upset with the timing of the blasts. With the Indian Mujahideen not claiming responsibility like it did in emails sent at the time of the Ahmedabad and Delhi blasts, investigators are now toying with the theory that the blasts were carried out by a second group — probably linked indirectly to the Indian Mujahideen.

The theory has come about after the interrogation of Syed Noushad, a 25-year-old taken into custody by the Mumbai Crime Branch as part of its investigation into the Indian Mujahideen network, from Mangalore on October 3. Noushad has during interrogation told the police that he overheard Bhatkal questioning an unidentified person about the timing of the July 25 blast when the Ahmedabad blasts had been scheduled. “Bhatkal seemed to know who carried out the blasts but he was unhappy with its timing and seemed to have been out of the loop of decision making. He is said to have stated that he would have prevented the July 25 blasts if he had known,” sources said.

Investigations are now leading to Abdul Sattar alias Salim who is suspected to be the supplier of the microchips for the Surat bombs on the basis of the interrogation of Syed Noushad. Sattar has been in telephonic contact with Bhatkal, investigators said.