Intelligence sources said when news of the Batla House encounter reached Dr Shahnawaz Alam, a top leader of the Azamgarh module, in Lucknow, he told all other members to leave the country.
Shahnawaz himself crossed over to Nepal with other IM operatives and reached a place called Butah. They procured forged Nepali passports and took a flight to Sharjah, where he regrouped with other top IM leaders Amir Raza Khan, Iqbal Bhatkal and his younger brother Riyaz Bhatkal.
Another top IM leader who managed to stay away from the security agencies' radar during the September 2008 crackdown was Yasin Bhatkal. He is now considered the operations chief of the IM in India.
Yasin took shelter in Darbhanga in Bihar after the Batla encounter and stayed there for one-and-a-half year, planning the next strike. Security sources say Yasin planted the bomb in German Bakery, which announced the regrouping of the IM.
The IM's Darbhanga module was detected by the security agencies in late 2011. The module had managed to form new hideouts in Tambaram in Tamil Nadu, Shaheen Bagh and Meer Vihar in New Delhi, Ranchi in Jharkhand and Hyderabad.
Security sources suspect Yasin Bhatkal also planted the bomb in Hyderabad's Dilsukhnagar in February this year.
"The IM is a prime suspect in the Bodh Gaya serial blasts as well. It shows that what started in Batla House was just the beginning of a constant war against the IM," said an investigator.