The security and intelligence agencies probing the Ahmedabad serial blasts on Wednesday said that there is something unusual with the way bombs were found unexploded in Surat.

The task of ascertaining that why the bombs remained unexploded has been given to the Directorate of Forensic Science (DFS). "We have sent the defused bombs to the DFS for a detailed analysis. After that only we will be able to ascertain why the bombs did not explode," said R S Brar, commissioner of police, Surat.

According to intelligence officials, the bombs planted in Surat had integrated circuits. The circuits were also complete, but the DFS will carry out analysis to find out why they did not explode. Meanwhile, the Gujarat police and intelligence agencies are surprised by way the terrorists carried out their operations in Surat.

'Why the bombs did not explode in Surat'

"It seems as if the terrorists decided to abort their mission at the last stage. Perhaps, they planted the bombs but backed out when it came to detonating them. It is hard to believe after their successful operation in Ahmedabad why they aborted their attack in Surat," an officer investigating the case said.

Meanwhile, sources in Forensic Science Laboratory (FSL) and Bomb Disposal Squad (BDS) said that the bombs were aligned through a signal receiving microchips. "The bombs were kept in a batch of three to four which were then aligned with a microchip with a common code. Unlike the bombs, which were found in Ahmedabad (detonator based), these bombs were heat based and some amount of heat was needed to assure the blast," a BDS officer said.

He further added that as the weather was comparatively cool in Surat, the explosive mixture could have failed in some cases.

However, a senior official present on the spot while the BDS went on defusing the bombs that were planted behind a hoarding and a tree, said, "Why and how would a terrorist plant the bombs on a tree and behind the hoarding? Moreover the way BDS defused them was also very uncanny. They were doing the job as if they have been doing that everyday."

Giving details of the way terrorists operate, a senior intelligence officer said that the most important thing for a terrorist is to first mix in the society and get out of the place as early as possible. "He can't risk getting caught. He can't do something unusual which will make him stand alone in the society and the way things happened in Surat it points out something very unusual," he said.