The mayor of Rutba described the IS assault on his town from three directions as “fierce”.
Imad Meshaal spoke of clashes in the centre between IS and security forces.
Kurdish Peshmerga forces have meanwhile carried out fresh attacks to the north-eastern town of Bashiqa, close to Mosul, which is occupied by IS. Over the last week, Iraqi and Kurdish forces have been battling IS in a belt of mostly uninhabited towns and villages around Mosul, contending with roadside bombs, snipers and suicide truck bombs.
The Mosul offensive involves more than 25,000 Iraqi ground forces as well as US-led coalition aircraft and advisers. It is expected to take weeks, if not months, to drive IS from Mosul, which is home to more than a million civilians.
Bashiqa is close to a military base of the same name where some 500 Turkish troops are training Sunni and Kurdish fighters for the Mosul offensive.
The presence of the Turkish troops has angered Iraq, which says it never gave them permission to enter the country and has called on them to withdraw. Turkey has refused the demand, insisting that it play a role in retaking Mosul from IS.
US Defence Secretary Ash Carter has visited both countries in recent days, and arrived in the Kurdish regional capital Irbil yesterday.
After meeting with Turkey’s leaders, Carter had announced an “agreement in principle” for Turkey to have a role in the operation. But Iraqi Prime Minister Haider al-Abadi insisted that Mosul was an “Iraqi battle.”
“I know that the Turks want to participate, we tell them thank you, this is something the Iraqis will handle and the Iraqis will liberate Mosul and the rest of the territories,” he said.
The forces taking part in the Mosul offensive include Iraqi troops, the peshmerga, Sunni tribal fighters and state-sanctioned Shiite militias.
Many fear the operation could heighten tensions between Iraq’s different communities, which are allied against IS but divided over a host of other issues, including the fate of territories near mostly Sunni Mosul that are claimed by the largely autonomous Kurdish region and the central government.
The UN agency for children meanwhile expressed concern over the more than 4,000 people it says have fled from areas around Mosul since the operation began.