Riyaz Bhatkal, the LeT operative in India who is also the founder of the Indian Mujahideen, was allegedly behind the blasts. In 2008, packages of Raja Gel-90 were recovered from his rented accommodation in Mangalore. Investigations revealed that Riyaz had supplied the explosive for the blasts in the three cities.
The Tamil Nadu police are, meanwhile,questioning two motorcycle brokers in Vellore to trace the buyers of the bike in which the bomb was hidden. Another person is also being questioned at Kancheepuram, said a police officer.