The Ahmedabad [Images] crime branch has obtained sketches of seven people who might be involved in the Jaipur [Images] bomb explosions in an effort to gather leads in the Ahmedabad serial blasts on July 26, a senior police official said on Tuesday.

"We have obtained seven sketches of suspects who could be involved in Jaipur bomb blasts. We are studying them for any link with Ahmedabad serial blasts," Joint Commissioner of Police Ashish Bhatia said.

The sketches will be studied by our experts and if needed, might be shown to the eye-witnesses, he said.

The crime branch has already prepared three sketches of possible suspects who could have planted bombs in the city.

Meanwhile, the Ahmedabad police conducted combing operations in various parts of the city on Monday.

Several teams from different police stations searched over 3,000 vehicles, 110 hotels and guest houses, 30 public gardens, various farm houses and 42 religious places. They also questioned 155 persons.

The Surat [Images] police is also questioning various suspects to get more information.

"We are still investigating the cases. There are some leads, which may suggest involvement of local Students Islamic Movement of India workers. We are still looking for concrete evidence in the cases," an official of Surat city police said.

Bomb squads have defused 24 explosive devices recovered from various places in Surat over the past one week.