India has proof that the Pakistan's intelligence agency ISI was behind the deadly Mumbai attacks. Sources have told NDTV that ISI trained the attackers.
The names of trainers and the places where meticulous training took place are also known to the government, the sources said.
The United States is believed to have even more evidence some of which it has shared with India, they said.
The US has told Pakistan that they have proof of terrorist outfit Lashkar-e-Taiba's role and sought the arrest of its chief Hafeez Sayeed.
Sources added it is hard to imagine that Pakistan army was not aware of Mumbai attack plan.
The deadly attacks on India's financial capital left 178, including several foreigners, dead.
Chairman of US Joint Chiefs of Staff Admiral Mike Mullen, who was in Pakistan on Wednesday, is believed to have told his Pakistani interlocutors that Washington had enough evidence to show a Pakistani hand in the attack, the sources said.