Ayatollah Sistani has dismissed the concept of exacting revenge on ISIS terrorists taken captive, according to a Farsi report by SNN.
The senior cleric said the terrorists and their accomplices captured by Iraqi troops in Mosul should not be mistreated or tortured.
He said the mistreatment of ISIS captives is religiously and legally forbidden.
Ayatollah Sistani noted that the captives must be handed over to the Judiciary, and stressed the need to protect the lives of citizens.
A large number of ISIS militants were taken captive by Iraqi force in the operation to liberate Mosul.
ISIS militants made swift advances in northern and western Iraq over the summer of 2014, after capturing swaths of northern Syria.
Afterwards, a combination of concentrated attacks by the Iraqi military and the volunteer forces, who rushed to take arms after Ayatollah Sistani issued a fatwa calling for the fight against the militants, blunted the edge of ISIS offensive and forced the terrorist group withdraw from much of the areas it had occupied.
The northern city of Mosul was finally liberated a few days ago.
