According to Indian web site Tehelka.com, Indian government had received the vital and significant intelligence five days before Mumbai attacks which had been simply ignored. The mobile numbers that were used by the Mumbai terrorists were available with the Intelligence Bureau at least five days before 26/11.
Highly placed sources shared the contents of a ‘Secret’ note that contains 35 mobile numbers. Out Of the 35 SIM cards, 32 had been purchased from Kolkata and three from Delhi and sent to Pakistan-administered Kashmir by mid- November.
That crucial and stunning piece of information was received by the Intelligence Bureau (IB) on 21 November, at least five full days before Ajmal Amir Kasav, the lone surviving terrorist and his nine accomplices reached Mumbai.
The Prime Minister and Home Minister are aware that for all the five crucial days that the numbers were available, they were not being monitored. The lapse is all the more critical because at least three of the 32 numbers contained in the Secret note, were the exact same cell numbers that the Mumbai terrorists used to keep in touch with their handlers.
It is well possible that the terrorists only activated their mobile numbers after reaching Mumbai but that does not excuse the fact that the numbers were not put under surveillance despite the knowledge that they had been sent to terrorists.
On 18 September, the Research and Analysis Wing (RAW) had intercepted a satellite phone conversation, which clearly indicated that a hotel at the Gateway of India in Mumbai would be targeted. Crucially, the intercept also revealed that the sea route would be used to launch this operation. Again, on 24 September, RAW recorded another conversation. This time, the hotels were mentioned by name and they included the Taj, the Sea Rock Hotel and the Marriott hotel
Security breached ease with which Mumbai came under attack brought back the question of internal security.