geneva iraq capable try atrocities commit islamic state battle mosul must find rout justice international criminal court icc u.n. human right report say thursday least 2,521 civilians kill nine-month battle include 741 people execute report say die result islamic state isil attack cite testimonies mass abductions islamic state well kill use human shield deliberate target civilians home isil plant huge number improvise explosive devices use drone drop explosives mosul city 1.5 million well set fire sulphur field oil well say force desecrate religious sit last june blow al-nuri mosque leader abu bakr al-baghdadi declare caliphate span part iraq syria 2014 say iraqi court tribunals jurisdiction international crimes genocide crimes humanity war crimes prosecutors police investigators judge lack capacity ... investigate charge try persons relation crimes report say call amend domestic law iraqi law enough guarantee due process fair trials say accept jurisdiction hague-based icc find ways ensure crimes try competent court would reassure international community iraq serious get justice key rebuild trust reconciliation say atleast 74 massgraveshave discover since june 2014 areas previouslyheld isilin iraq u.n. report say include sinjar northwestern city u.n. say islamic state commit genocide kurdish-speaking yazidi religious minority sunni militants view infidels iraq international community duty ensure crimes prosecute syracuse university professor former war crimes prosecutor david crane say wednesday separate report genocide issue law school syrian accountability project bring isis justice genocide yazidi community domestic international level depend strategic preservation forensic evidence crane report say u.n. report also call iraqi authorities investigate crimes allegedly commit iraqi-backed force operation include mass abductions unlawful kill call separate investigation air strike international coalition say u.n. record 461 civilian deaths air strike intensive phase battle western mosul feb. 19. iraq equip try islamic state 's atrocities mosul u.n