In a major development, Maharashtra's Anti-Terrorist Squad (ATS) today arrested Asif Khan Bashir Khan alias Junaid, the suspected prime conspirator of the July 11 train blasts planned by Pakistan's ISI, from Belgaum in neighbouring Karnataka.An ATS officer told PTI that Junaid was "the prime person in the entire conspiracy." With his arrest, the number of suspects arrested in connection with the blasts has gone up to 16.Junaid, suspected to be an activist of banned Students Islamic Movement of India (SIMI), has been brought to Mumbai, the official said, without elaborating on his exact role in the terror attacks on Mumbai's lifeline.Police sources said Junaid hails from Jalgaon in North Maharashtra and is believed to be one of the three absconding Indians who had allegedly planted the bombs along with Pakistanis in the suburban trains.Junaid is also wanted in a criminal case in Jalgaon concerning alleged subversive activities of Lashkar-e-Taiba (LeT).Seven bombs ripped through the suburban trains during peak hours killing nearly 200 people. Police have said the attack was planned by Pakistan's ISI and executed by LeT and SIMI.