As two more live bomb were recovered in Surat [Images], Central security agencies were still groping in the dark about the perpetrators of the terror acts in Gujarat, which claimed 53 lives.

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"Investigators are working on certain leads. But right now we have nothing to share," a top Union Home Ministry official said.

The Home Ministry, which is in constant touch with Gujarat government officials, is helping in probing the serial explosions as well recovery of 21 bombs in Surat.

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"The bombs found in Surat have striking similarity with bombs used in Bangalore as in both places the explosives were made using Integrated Circuits," the official said.

Bombs fitted with timers were used in the Ahmedabad [Images] serials explosions.

The Home Ministry is worried over the fact that a large number of posts in Gujarat Police are lying vacant, hampering proper policing as well investigations into crimes.

"In Surat alone, out of the total strength of 3,500 police personnel, 500 to 700 posts are presently lying vacant," the official said.

The Centre is now contemplating to ask all state governments to start the process of recruitment two-three years in advance anticipating vacancy.

"We have already started such a practice in central forces like the Central Reserve Police Force and the Border Security Force. This is very helpful. We want the states to follow it at their level too," he said.

A live bomb was found at Varacha locality in Surat on Wednesday shortly after a visit to the area by Gujarat Chief Minister Narendra Modi [Images].