The UN's special Iraq envoy on Saturday condemned attacks by armed entities amid ongoing protests in Iraq and urged authorities to bring them to justice, reports Anadolu Agency.
At least 16 people were killed in an armed attack by unidentified assailants in the capital Baghdad late Friday.
"The deliberate killing of unarmed protestors by armed elements is nothing less than an atrocity against the people of Iraq," said Jeanine Hennis-Plasschaert, the secretary-general's envoy.
She added: "The perpetrators must be identified and brought to justice without delay."
Iraq has been rocked by mass protests since early October, leaving 460 Iraqis dead and 17,000 injured, according to Iraq's High Commission for Human Rights.
On December 1, the Iraqi parliament accepted the resignation of Prime Minister Adel Abdul-Mahdi amid protests against corruption and poor living conditions.