The powerful explosion inside the mosque in May 2007 had killed at least 14 people; the twin blasts in Hyderabad left 45 people dead. In 2011, the NIA arrested, and subsequently chargesheeted, Hindu fundamentalists for bombing the masjid.
Yasin, who is now in NIAs custody, has reportedly admitted training the Hyderabad bombers, including Akbar Ismail Chaudhary, who has since been arrested, and his brother Mohsin Chaudhary, a resident of Pune who is absconding. Yasin has also reportedly revealed names of some of the other absconding operatives of the IMs south module.
The bombers were trained in the use of explosives and IEDs for two weeks at a farm house in Chikamagalur, Karnataka. The trainees were also shown videos of the US war in Afghanistan and on the life of Osama bin Laden to motivate them. After the training, Yasin reportedly claimed, each recruit was given a CD containing lectures and a manual for the manufacture and use of explosives and IEDs. During this time, Yasin went by the name of Waseem, officials said.
The plot for the Hyderabad blasts was devised at a flat in Ashok Muse neighbourhood of Pune. The flat, in which Iqbal Bhatkal and Riyaz stayed, was raided by the Maharashtra ATS after the arrest of scores of IM operatives in September 2008.
Yasin told his interrogators that it was Riyaz who chose the sites of the 2007 blasts. He was disturbed over the Mecca Masjid bombing as several Muslims had died in the blast and police had also resorted to firing at that time, Yasin claimed.
In the first week of August 2007, Riyaz asked Akbar Ismail Chaudhary and another associate to do a recce of populated areas of Hyderabad. The targets chosen included Dilsukhnagar, Yasin said, but the the bomb planted there did not explode due to some malfunction.
In February 2013, twin explosions rocked Dilsukhnagar and killed at least 20 persons. Investigations have pointed to the role of IM and Yasin is alleged to have been one of the bombers.
Investigators, meanwhile, said they are yet to corroborate Yasins claims.