So far, the investigators believed Aseemanand was more of an ideologue than an activist. But official sources say he had roped in Sandeep Dange, an engineering graduate, and Ramji Kalsangra, an electrician, to build the improvised explosive devices used in the blasts. Around midnight on February 18, 2007 — a day before Pakistan foreign minister Khurshid Mahmud Kasuri was to arrive in Delhi to resume peace talks — bombs were set off on the Delhi-Lahore Samjhauta Express, a twice-a-week service.
The incident occurred on Indian territory, after the train passed Diwana station near Panipat in Haryana, 80 km north of Delhi. Of the 68 killed, most were Pakistani civilians, besides some Indian citizens and army jawans guarding the train.
The sources say the ingredients and the structure of the firebombs — called incendiary devices — were highly sophisticated and innovative and was quite unique till then.
It was also clear that the bomb-maker had expertise also in dealing with electronics. The NIA suspects RSS district functionary Dange of helping Kalasangra, a resident of Indore, from where the suitcases had been brought. Both are yet to be apprehended. Swami Aseemanand, born as Jatin Chatterjee in West Bengal, got a masters degree in Physics from the Burdwan University. He joined the Vanvasi Kalyan Ashram, inspired by the Rashtriya Swayamsevak Sangh in 1978. His name surfaced during the probe into the blasts at Mecca Masjid on May 18, 2007, Ajmer on October 11, 2007 and Malegaon and Modasa on September 29, 2008. He was arrested from Haridwar in November this year in connection with the Mecca Masjid blast.