The UN report, Jayalalithaa said, "made mincemeat of the Lankan government's claim that it had conducted a humanitarian rescue operation with a zero civilian casualty policy."
Jayalalithaa demanded that Rajapaksa be tried for war crimes and genocide, "along with his generals and senior ministers who were party to the brutal excesses."
Referring to Rajapaksa's statement that the report could prove to be a hindrance to reconciliation that was under way, she said the "Sri Lankan Government did its best to see that this report did not see the light of day."
"India can no longer remain a silent spectator," said the AIADMK leader and added, "If necessary, an economic blockade will have to be resorted to to bring a recalcitrant Sri Lanka to heel."
The UN report on the Lankan civil war released in New York on Monday said most of the civilians lost their lives during shelling by Sri Lankan troops in the final stages of the war with the Liberation Tigers of Tamil Eelam (LTTE) in 2009. The UN panel estimated 40,000 people were killed in the conflict.