Agnes Callamard, U.N. Special Rapporteur on Extra-Judicial Summary or Arbitrary Executions, talking to reporters in Baghdad, Iraq, Thursday, Nov. 23, 2017. Callamard called on the Iraqi government to speed up investigations into allegations of human rights violations committed by security forces during the fight against the Islamic State group and to make the results of those probes public. (AP Photo/Karim Kadim)

BAGHDAD - A top United Nations official Thursday called on the Iraqi government to speed up investigations into allegations of human rights violations committed by security forces during the fight against the Islamic State group and to make the results of those probes public.

Since 2014, the U.S.-backed Iraqi forces' fight against the Sunni militant group has been mired in violations committed by government forces and paramilitaries that international human rights groups have decried as war crimes, ranging from extrajudicial killings of IS suspects to forced displacement and detention of civilians.

On Friday, Iraqi forces drove IS militants from the last Iraqi town near the Syrian borders more than three years after the militant group stormed nearly a third of Iraqi territory, keeping the militants scattered in a wide desert area to the west and north of Baghdad.

Concluding an official visit to Iraq, Agnes Callamard, the U.N.'s special investigator on extra-judicial executions, stressed to the Iraqi officials on "the importance of translating the military defeat over ISIS into victories for accountability and over impunity." ISIS is another acronym for IS.

Callamard told reporters in Baghdad that Iraq's new "transition phase" presents "both opportunities and challenges" and that the government should "respond effectively and impartially to allegations of violations in order to build and strengthen confidence."

The Iraqi government has previously acknowledged some of the allegations, but insisted that these were "individual acts" and promised to investigate them and punish the perpetrators. No outcomes have been published by the government on these investigations.

Callamard discussed with officials from the government and Shiite-dominated paramilitary troops known as Popular Mobilization Forces, "six or seven large scale allegations," including disappearances around Fallujah west of Baghdad and the killing of some prisoners before the June 2014 IS onslaught. She didn't divulge more details on other allegations, expecting to receive the results within "a week or two."

She said that "investigations have already taken place, but the problem is that there is not transparent reporting on the outcomes of those investigations."

Also on Thursday, the Iraqi Army and PMF launched a new military operation to clear the al-Jazeera area from IS militants, said a statement. The area is in a swath of desert between Salahuddin, Anbar and Ninevah provinces north of the capital. During his weekly news conference on Tuesday, Iraqi Prime Minister Haider al-Abadi said that chasing down IS militants in the al-Jazeera area and the western desert will be the last stage before declaring the final victory over IS.

News from © The Associated Press, 2017