Based on intelligence reports, the Uttar Pradesh police now believe that the masterminds of the Varanasi blast may be Asadullah Akhthar and Dr Shahnawaz. The Bhatkal brothers -- Riyaz and Iqbal -- are also suspected to have helped plan the blast, said sources.
According to sources in the Intelligence Bureau, all four suspects are hiding in Sharjah, where the terror attack had been planned.
While tracking the movements of Riyaz Bhatkal, investigating agencies have found that he has visited Sharjah several times from his base Karachi.
According to preliminary leads, the Bhatkal brothers helped plan the operation while Shahnawaz and Asadullah carried out the strike.
Iqbal Bhatkal or Iqbal Shahbandri, who hails from the coastal town of Bhatkal in Karnataka, went missing two years ago. He was accused of working for the Indian Mujahideen along with his brother Riyaz. Residents of Bhatkal claim that Iqbal fled the country, fearing his imminent arrest as he had been 'framed' in a case.
Investigators believe that Iqbal ran a terror module in Pune and recruited cadres for IM's modules in Maharashtra and Pune.
Intelligence agencies first heard of Shahnawaz and Asadullah in the aftermath of the Delhi serial blasts and after the controversial Batla House encounter.
Shahnawaz's brother Mohammad Saif was arrested in connection with the Batla House encounter. The IB had then warned that he may try to regroup the IM and carry out retaliatory strikes to avenge the incident.
Shahnawaz, a doctor and Asadullah, a pharmacist, hail from Azamgarh in Uttar Pradesh. They initially joined the Students Islamic Movement of India but moved to the Indian Mujahideen four years ago.
Shanawaz, who worked as a doctor in a Lucknow hospital for two years, visited Varanasi several times, said sources.
Asadullah, who assembled the bombs for the 2008 Delhi blasts, left India after the terror strike. He has allegedly planted the bomb at Greater Kailash.
According to sources in the IB, Asadullah was part of the core group of the IM when the terror outfit was founded. His first tryst with terror was during the Jaipur blasts in 2008, in which he was named as one of the accused.