Updated

A top U.N. official has 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.

Agnes Callamard, U.N. Special Rapporteur on Extra-Judicial Summary or Arbitrary Executions, says Iraq's new "transition phase" presents "both opportunities and challenges"

Callamard said on Thursday that the government should "respond effectively and impartially to allegations of violations in order to build and strengthen confidence."

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 to civilians.