The Islamic State has surrendered the key town of Baaj in north-west Iraq, which was a known hideout of the terrorist group's leader Abu Bakr al-Baghdadi.
Baaj had been under Islamist militants' control throughout the 14 years of war and insurgency.
After the surrender, the remaining ISIS fighters fled the town on Saturday night, allowing Shia militia forces to enter unopposed.
"The Iraqi flag has been hoisted above its buildings," a statement from the Popular Mobilisation Front, which is an umbrella organisation for pro-government paramilitaries that is dominated by Iran-backed Shia militias, announced the "total liberation" of the Baaj district.
The withdrawal leaves just a pocket of Mosul and the border town of Bukamal as the only urban centres in Iraq with a significant ISIS presence.
Bukamal is expected to be a new focus of both Iranian and U.S. efforts.
Meanwhile, U.S.-backed Kurdish troops are now within sight of Raqqa on three sides of the city and the battle to retake the city is likely to start sometime this month.