"Amnesty International is particularly concerned by the reported formation in and around South Ossetia of irregular, locally organized armed groups able to act with impunity, increasing the potential dangers for civilians," the group said in a statement. It reported looting, burning and beatings.

"To be sure, there was indiscriminate and disproportionate use of force on both sides of the conflict," Anna Neistat of Human Rights Watch told a briefing earlier this week in Washington.

"However, the bulk of the looting and burning of property and attacks on civilians was conducted by South Ossetian militias and ordinary criminals who were allowed to operate in the areas controlled by Russian forces."