The United Nations has voiced disapproval of the execution of Saddam Hussein's two aides, with Secretary-General Ban Ki-moon saying that Baghdad disregarded UN appeals not to proceed with the death penalty.
UN spokesperson Michelle Montas said on Monday that Ban expressed "regret".
The UN High Commissioner for Human Rights, Louise Arbour, also raised the issue of fairness and impartiality in the execution of Barazan al-Tikriti, Saddam's half-brother and Awad al-Bandar, the former head of Iraq's Revolutionary Court.
They were hanged early Monday after they were convicted along with the former Iraqi president of the 1982 massacre of 148 Shia Muslims.
"The imposition of the death penalty after a trial and appeal proceeding that do not respect the principles of due process amounts to a violation of the right to life," Arbour said in a statement from her Geneva office.
The UN has called on governments to ban the death penalty, but cannot go against national laws that support it.
The hangings in Baghdad of Hussein's former aides took place two weeks after Saddam Hussein was himself executed for crimes against humanity.