"The report appears to be another attempt at castigating Sri Lanka for militarily defeating a ruthless terrorist group which has held the very people it claimed to represent as human shields," a statement from the external affairs ministry said.
The UN report issued on November 14 contended that their officials had failed to protect the Tamil civilians who were caught in the middle of heavy fighting.
The report seems to seek to endorse the baseless and discredited allegations of an exaggerated civilian casualty figure during the last stages of the conflict, which has not been agreed upon even among the senior UN officials at the time, the statement added.
While the report had admitted that the LTTE positioned its artillery among civilians, the allegation of government shelling into civilian concentrations does not take into account the principles of self-defence or reasonableness of retaliation, proportionality, or a technical analysis of the trajectories of the shells allegedly fired, to determine their source, the statement said.
Referring to reactions from other countries to the report, the statement contends that countries seem to disregard the fact that the basic purpose of the report was to engage in a critical appraisal of the UN system's performance.
"Ignoring this vital aspect, they have taken the opportunity to resort to criticism of the government of Sri Lanka in a manner that reflects patent bias and unwillingness to examine the developments with any degree of objectivity," it said.
Sri Lankan forces crushed Tamil rebels in May 2009 after nearly three decades of brutal fighting. The conflict claimed up to 1,00,000 lives, according to UN estimates, and both sides are accused of war crimes.