BAGHDAD - Shi'ite paramilitaries were preparing on Monday to deploy en masse to Iraq's western province of Anbar after Islamic State militants overran the local capital Ramadi in their biggest victory since last summer.
A spokesman for the Shi'ite paramilitaries known as Hashid Shaabi told Reuters they had received instructions to mobilise, but the timing and scale of the deployment could not be revealed for security reasons.
"Now that the Hashid has received the order to march forth, they will definitely take part," said Ali al-Sarai, a member of the Hashid Shaabi's media wing.
"They were waiting for this order and now they have it." Shi'ite militias backed by Iran have played a leading role in driving back the insurgents elsewhere in Iraq, but have so far been kept on the sidelines in Sunni-dominated Anbar for fear out of concern they could provoke a sectarian backlash.
But the security forces have struggled to make progress on their own in Iraq's largest governorate, and on Sunday withdrew from some of the last districts they held in the city of Ramadi, west of Baghdad.
Islamic State claimed full control over the city and said it had seized tanks and other weapons left behind by the security forces in an echo of the fall of Mosul last June, when the army's northern divisions disintegrated.