Iraq's top diplomat says the "toxic" proliferation of extremist groups among Syria's rebels raises the prospect of a jihadist-ruled territory at the heart of the region.

Iraqi Foreign Minister Hoshyar Zebari told attendees at a security conference in Bahrain on Saturday that the increase in radical fighters in the armed opposition to Syrian President Bashar Assad is leading toward the creation of an ungovernable "Islamic emirate" that the world will have to deal with down the road.

Iraq is grappling with a months-long spike in bloodshed blamed largely on al-Qaeda's local franchise, which is also playing an active role inside Syria in the fight against Assad.