Prime Minister Manmohan Singh made the comments during a security conference in New Delhi Monday, reportedly saying, "Given the sophistication and military precision of the attack, it must have had the support of some official agencies in Pakistan," The New York Times reported Tuesday.

Singh made the comments after India handed over to Pakistan what Indian leaders said was evidence linking Pakistan to an alleged "conspiracy" born in that country.

Indian Foreign Secretary Shiv Shankar Menon declined to say whether the suspected Mumbai conspirators were linked to current or retired officials, only that it was unlikely a raid such as the one carried out in Mumbai "could occur without anybody anywhere in the establishment knowing it was happening."

Mahmud Ali Durrani, adviser to the Pakistan prime minister on national security, said he believes Singh's comments are "unfortunate," the Press Trust of India reported.

Both countries should avoid a "blame game," and India should let Pakistan finish its investigation into the attacks on India's financial and entertainment hub that left roughly 170 dead, Durrani told Dawn News.

Richard Boucher, U.S. assistant secretary of state, said in the region Monday it was "clear" the attackers had "links that lead to Pakistani soil," but that Pakistani authorities have arrested a number of people suspected in different aspects of the attacks.

Boucher declined to answer a question about whether evidence suggested the Pakistani government was either directly or indirectly involved, the Times said. He urged leaders of the two countries to work together to bring the Mumbai attackers to justice.