Investigators believe that the clip was recorded nearly a month ago and the house could be the place where the bombs were assembled. As Jaipur has trains to Delhi, Ajmer and Kota, investigators are now focusing on houses along the 20-km railway track that runs across the Rajasthan capital.

After piecing the clues available so far and interviewing the lead investigators in the case, The Sunday Express found:

• Neither the Central nor State intelligence apparatus was able to pick up the presence of 18-20 persons, in all probability from western Uttar Pradesh and Bangladesh, in Jaipur, who might have had a connection with the blasts.

• Top intelligence sources are more or less certain that the decision to target Jaipur was taken more than a month ago in Pakistan with Bangladesh-based HUJI terror group used as the tool. The basic ingredients to build the improvised explosive device used in the attacks were all commercially procured near Jaipur — the ammonium nitrate slurry, APCL detonators, Samay alarm clock, wonder tape and wooden casing, all of which were then put in bags.

• None of the clues that investigators are examining now are unfamiliar since the bomb blast in October 2005 in Delhi. Also, like in Jaipur, bombs were defused after the blasts on the Samjhauta Express, and in Delhi, Malegoan, Sankat Mochan, outside a Lucknow court and Hyderabad.

Teams from Mumbai, UP and Delhi anti-terrorism squads have landed in Jaipur and the investigation is broadly focused on the following:

• The two other video clips have been taken near Kotwali, which was targeted on May 13.

• The cycles were purchased between 2.30-3.30 pm, just hours before the blasts. The literature of Al-Hindi, as mentioned in the e-mail, was recovered by the UP STF from Hardoi after the failed Sitapur blast on May 26, 2007.

• Explosive vendors around Jaipur stone quarries are being questioned with the help of Controller of Explosives. The defused bomb does not contain RDX.

• Communications for the past one month are being tracked down in the hope that the bombers may have slipped up. Samjhauta Express blast investigations are still hinged on this technical input but then the bombers are known to maintain radio silence since the Sankat Mochan blast.

• Although the Maharashtra police believes that HUJI’s India chief Shahid Bilal is alive and shuttling from Bangladesh to Karachi, the Jaipur police has been told that Bilal is dead and the HUJI operations are now being handled by Mohammed Amjad.