Security agencies today interrogated the four suspects arrested for their alleged involvement in the serial blasts at the site of Narendra Modi's rally here in October last year.
The four terror suspects - Haider Ali alias Black Beauty, Numan Ansari, Mojibullah Ansari and Taufiq Ansari -allegedly members of Indian Mujahideen (IM), were produced before the court of special NIA judge A K Singh yesterday who granted police remand to NIA.
NIA officials, police personnel, Intelligence Bureau (IB) officials and other security agencies interrogated the four suspects who were kept in Bihar Military Police (5) campus for security reasons, sources said.
Utmost secrecy was maintained with heavy police security cover for the suspects and the investigating officials.
"The investigators are trying to get a blow-by-blow account of the planning done for the blast at Narendra Modi's rally in Patna last October... Efforts are on to trace other acquaintances of the suspects in Bihar," sources said.
So far, 13 suspects connected with the blasts, in which seven persons were killed and several others injured, have been nabbed from various parts of Bihar, Jharkhand, Uttar Pradesh and Chhatisgarh.
"Since they are associated with the IM which functions with the help of its various modules, efforts are on to find out the existence of such modules in Bihar and Nepal," sources alleged.
NIA sleuths are also trying to trace how the explosives were transported, assembled, distributed and then taken to the blast sites, they added.
It was learnt that Noman, Taufiq and Mojibullah, also accused in the Bodh Gaya blasts last July, might be taken to the sites as a part of the investigation, they said.
"The suspects could be taken to blast sites in Patna and Bodh Gaya also. It's a routine part of the standard investigation process," they said.
