"It is not possible for the intelligence and the security people to keep a tab on everything, everywhere," he said.
Security experts and ex-top sleuths said that terrorists were outdoing Indian Intelligence agencies and it was unfair to call Jul 13, Mumbai blasts an intelligence failure.
Adding further they said that terrorists were growing in numbers, had access to weapons and were successful in finding new ways to strike.
"The intelligence agencies are getting outwitted. But to be fair to them, we must concede that they have a difficult job. Every now and then, you hear new terrorist groups are cropping up," said Samanta.
"Then, there are sleeper cells which suddenly activate, cause a terrorist activity and again go dormant," he said.
Samanta who also worked as a Director General, Intelligence, West Bengal Police said that Kolkata was also equally under threat.
"Because of its geographical position, terrorists may sneak in, cause a blast and then easily escape through the borders," he said.
"I won't call it an intelligence failure or a security lapse. The terrorists are always on the lookout for opportunities and whenever they get a chance, they strike. They always choose a soft target. Why don't they attack high security areas?" said ex police commissioner, Prasun Mukherjee.
"The police are already much stretched and one cannot be on high alert all the time. Whenever there is such activity, people clamour about intelligence failure but when the agencies foil any attack, why is there no publicity?" asked Mukherjee.