Two key members of the Students Islamic Movement of India, who were part of the core group that executed the blasts in Ahmedabad [Images], are still absconding, according to crime branch sources.

The police are also tracking over 50 small time operatives who were involved in executing the blasts in Ahmedabad and planting the bombs in Surat [Images].

How the Ahmedabad blasts case was solved

"Our job is not over yet. We are in search of two other culprits who were involved in the blasts. They are Taufiq Bilal, a Mumbai-based techie and Qayamuddin, a Vadodara resident. Many others involved were small operatives who are yet to be nabbed," crime branch sources said.

Mumbai-based computer engineer Taufiq Bilal, whom the Joint Commissioner of Police Ashish Bhatia described as another mastermind in the serial blasts case, is believed to have assembled the bombs used in Ahmedabad, police said.

Coverage: Ahmedabad Blasts

Taufiq, who was working with a subsidiary of IT giant Wipro [Get Quote], is believed to have assembled the bombs three to four days prior to the blasts on July 26, police said, adding that he had left the state before the explosions.

Investigators say Indian Mujahideen is SIMI, V2.0

The police also suspect his involvement in hacking the computer of American resident Ken Haywood, from whose Internet Protocol address the threatening e-mail, claiming responsibility of the blasts by Indian Mujahideen [Images], was sent to television channels.

"Qayamuddin managed the logistics and was also involved in procurement of material used in the explosives. He had made a base in Ahmedabad and stayed here for about two months," police said.

Breakthrough in Ahmedabad blasts case

Qayamuddin is considered very close to SIMI [Images] breakaway group chief Safdar Nagori, who was arrested by the Madhya Pradesh [Images] police in March 2008.

The police believe that Qayamuddin and Abu Bashir had guided those who planted the explosives in Ahmedabad.

"We have kept a watch at several places to track these two people," crime branch officials said.