India has warned Pakistan of a massive retaliation even if there is a midget nuclear strike by the neighboring country, local media reported Tuesday.

"India will not be the first to use nuclear weapons, but if it is attacked with such weapons, it would engage in nuclear retaliation which will be massive and designed to inflict unacceptable damage on its adversary. The label on a nuclear weapon used for attacking India, strategic or tactical, is irrelevant from the Indian perspective," 'The Times of India' quoted Shyam Saran, the convener of the National Security Advisory Board, as saying.

Slamming Islamabad for its role in the Mumbai massacre, in which over 170 people were killed by 10 Pakistani militants in November 2008, Saran said "What Pakistan is signalling to India and to the world is that India should not contemplate retaliation even if there is another Mumbai because Pakistan has lowered the threshold of nuclear use to the theater level. This is nothing short of nuclear blackmail, no difference from the irresponsible behaviour one witnesses in North Korea."

Issuing a stern warning to Pakistan, the former Indian foreign secretary added "A limited nuclear war is a contradiction in terms. Any nuclear exchange, once initiated, would swiftly and inexorably escalate to the strategic level. Pakistan would be prudent not to assume otherwise as it sometimes appears to do, most recently by developing and perhaps deploying theater nuclear weapons."

India and Pakistan are arch-rivals and have fought at least three major wars over the disputed territory of Kashmir in the last 60 years.