Iraq forces attack IS-held town of Hawija: general
"A huge military operation has begun to liberate Hawija and its surrounding areas," Lieutenant General Abdel Amir Yarallah said in a statement.
Iraq began preparing the operation to retake the militant-held enclave around Hawija on September 21, swiftly taking the town of Sharqat on its second day before pushing on towards Hawija itself.
Yarallah said that Friday's assault marked the second phase of the operation and aimed to recapture Hawija and the towns of al-Abbasi, Riyadh and Rashad to its west, east and south.
All are mainly Sunni Arab towns that have long been bastions of insurgency and were bypassed by government forces in their push north on second city Mosul last year which culminated in the jihadists' defeat in their most emblematic stronghold this July.
Yarallah said that troops were now advancing on the town of al-Abbasi.
He said the operation involved the army, the federal police, counterterrorism units and the Rapid Intervention Force, as well as tribal volunteers and the paramilitary Popular Mobilisation force.
Prime Minister Haider al-Abadi hailed the second phase of the operation to recapture the area.
"As we promised the sons of our country, we are going to liberate every inch of Iraqi land and crush the Daesh (IS) terrorist gangs," Abadi said.
"We are on the verge of a new victory to liberate the residents of these areas from those criminals."
The Hawija enclave is one of just two areas of Iraq still held by IS, along with a stretch of the Euphrates Valley near the border with Syria.
The latest offensive against the militants comes just hours after the Islamic State group published an alleged recording from its leader Abu Bakr Al-Baghdadi via its propaganda outlet Al-Furqan media.
It comes amid speculations over Baghdadi's fate following recent reports that he was killed after a Russian airstrike hit a convoy of senior IS commanders near Raqqa.