baghdad iraqi shi ite paramilitary group take part war islamic state militants incorporate state security body nation top shi ite cleric say message deliver friday sermon holy city kerbala one representatives grand ayatollah ali al-sistani say weapons use fight insurgents bring control iraqi government sistani position line prime minister haider al-abadi want prevent commanders militias know popular mobilisation force pmf use power clout acquire war elections due may 12. sistani author landmark fatwa religious decree urge iraqis volunteer war islamic state government arm force collapse 2014 militants sweep towards gate baghdad victory daesh mean end battle terrorism sistani representative sheikh abdulmehdi al-karbalai say mention existence sleeper cells security apparatus support fighters take part war daesh add sermon broadcast state tv use arab acronym islamic state necessary absorb fighters official constitutional structure sistani say sermon add fatwa use achieve political aim abadi quickly react sistani sermon statement office welcome call use volunteer fighters political campaign iraq sunni kurdish politicians call abadi declare victory islamic state last week disarm pmf say militias responsible widespread abuse include extra-judicial kill kidnappings displace non-shi ite populations effect report tehran government baghdad pmf say abuse isolate incidents systematic commit punish two important iranian-backed paramilitary leaders hadi al-amiri qais al-khazali announce week put militias abadi order decision formally separate arm political wing could pave way contest elections possibly part broad alliance close iran iran provide train supply weapons powerful pmf group include amiri badr organisation khazali asaib ahl al-haq iraqi parliament last year vote establish pmf separate military corps report abadi capacity commander-in-chief arm force top iraqi shi'ite cleric say paramilitaries part state security body