India has proof that ISI was involved in planning the Mumbai terror attacks and training the terrorists who killed 183 people during a 60-hour siege of the country's financial capital, sources said. The names of trainers and the places where meticulous training took place are also known to the Govt.

Adding to the suspicions of Pakistan's ISI being linked to the Mumbai terror attacks, Afghanistan said intelligence gathered after the carnage has linked the agency to the unprecedented strike.

Airports across the country were put on high alert in the wake of intelligence reports that terrorists from Pakistan or Afghanistan may strike using a hijacked airport even as the Indian Air Force said it is prepared to counter a 9/11 type aerial attack on New York.

Defence Minister A K Antony wanted tightening of vigil along India's coastal, land and aerial frontiers to prevent terror attacks in future.

Ten SIM cards were bought a month back from three different locations in Kolkata and sent to Pakistan via Bangladesh.