Amnesty International says decades of reckless arms trading and the poorly regulated flow of weapons into Iraq have contributed to the accumulation of a "vast and varied" arsenal of weaponry by Islamic State (IS) militants.
In a report issued on December 8, Amnesty International says IS militants are using the weaponry to commit war crimes on a massive scale in Iraq and Syria.
The report says most of the extremist group's weapons, ammunition, and equipment were looted from the Iraqi Army.
It says the weapons were manufactured and designed in more than two dozen countries -- including Russia, China, the United States, and member states of the European Union.
It says IS militants have also seized weapons from Syrian government forces after capturing military bases there.
Amnesty International called on all states to adopt "a complete embargo" on Syrian government forces and armed opposition groups "implicated in committing war crimes."
Based on reporting by AP and AFP