Central security agencies said that the banned Harkat-ul-Jehadi Islami (Huji) militant outfit from Bangladesh was possibly behind the twin blasts. It was suspected that Shahid and Bilal or Sahid Ilyas Bilal, who were the masterminds of the Mecca masjid blast were also behind Saturday's explosion. Shahid is reported to be in Karachi, Pakistan, and is instrumental in recruiting people for arms training from Hyderabad. Shahid Ilyas Bilal, who is also linked to the Mecca Masjid attacks is a high-ranking Lashkar-e-Taiba operative who has lately been working with Huji.
The government of Andhra Pradesh blamed terrorist groups based in Bangladesh and Pakistan for the two blasts. After an emergency meeting of the state cabinet, Chief Minister Y. S. Rajasekhara Reddy told reporters that "the available information points to the involvement of international terrorist organisations in Bangladesh and Pakistan". India's neighbours harbour a lot of fundamentalist and militant organisations, making her prone to blame other countries for such activities.
Madhukar Gupta, Union Home Secretary, has said that security agencies and state police suspect Lashkar-e-Toiba or Jaish-e-Mohammed. Shivraj Patil Minister for Home Affairs (India),specified terror groups based in Pakistan and Bangladesh were involved in the attacks.
On 26 August, Foreign Affairs Adviser of Bangladesh Iftekhar Ahmed Chowdhury described claims linking Bangladesh with the bombings as 'baseless'.
Pakistan has denied accusations that its country was involved in the blasts and cautioned India against finger-pointing before carrying out proper investigations into such terror attacks. Foreign Office spokesperson Tasnim Aslam said, "These are terrorist attacks and we condemn them. We are ourselves victims of terrorism and remain committed to fighting terrorism. It is always better to investigate rather than to speculate,"
As investigators searched for clues, an expert said the explosives used in yesterday's blasts and the Mecca Masjid attack were different. "In the Mecca Masjid blasts, it was a RDX and TNT mixture...here it is entirely different (as some) ammonium nitrate-based chemical (was used)," said T Suresh, chief scientific officer of the CLUES bomb detection squad.
On 27 August, the Hyderabad police released the news that the bombs were constructed from Neogel-90, an ammonium nitrate-based explosive used commercially in road construction. The Telegraph reported that this caused suspicion to be 'divided' between the Huji, which is known to have used Neogel in the past, and Naxalite organisations from the interior of Andhra Pradesh, who have been "planning retaliation for the state government’s hot-pursuit campaign"; Neogel-90 has not previously been used illegally in India, but has been seized in the past from Naxalite groups in Kerala and Nepal.
Read more about this topic: 25 August 2007 Hyderabad Bombings