Investigations being conducted by the MP police into the backgrounds of the three suspected terrorists arrested in connection with the Bhopal-Ujjain train blast, the first known ISIS operation in India, have revealed an AMU connection.According to police sources, two of the arrested suspects Syed Mir Hussain alias Humza and Aatish Muzaffar alias Al Kasim, who nabbed along with Danish Akhtar alias Jaffar, had studied in Aligarh Muslim University . Though details about their educational background are still sketchy, sources said while Syed Mir Hussain had done his BA, Aatish Muzaffar had dropped out from a diploma course at the University in 2011-12.Sources said an Aadhar card (number available with TOI) found in possession of Syed Mir Hussain, mentioning his address as house number 6, Indra Nagar, Aligarh, sent the police on his trail to the city. Sources said the MP ATS had sent this information to the Aligarh police last night, when the police encounter with the alleged ISIS operative, Mohammad Saifurullah alias Ali, who was also involved in the train blast, was underway in Lucknow.Subsequent investigation conducted through the night by the local police revealed that though Syed Mir Hussain and Aatish no longer stayed in Aligarh, they had studied at AMU.Talking to TOI, MP Inspector General (Intelligence), Makarand Deoskar said preliminary inquiries from Syed Mir Hussain have revealed that while he hails from Kannauj, he had done his graduation (BA) from Aligarh Muslim University (AMU). He said information about his address have been sent to the Aligarh police.ADG (law & order) of Uttar Pradesh, Daljit Chaudhary, also confirmed to TOI that Hussain hails from Kannauj and his background is being looked into.Sources said the AMU connection with the Bhopal blast has caused considerable concern among security officials. AMU could now be under the radar of the investigating agencies in a big way, sources claimed.