It is very evident that blasts have been carefully synchronized and meticulously planned. All the 8 blasts happened in regular intervals in a space of 12 minutes. The intelligence agencies believe that cycles have been used to trigger the blasts. There has also been email from a little known terrorist group Indian Mujahideen, sent accompanied with a video clipping of a cycle with a bomb tied on the seat. The intelligence is still checking on the veracity of these clips. The Home Ministry has reasons to believe that the banned Bangladeshi terrorist outfit Harkat-ul-Jehadi Islami has engineered the blasts.