Islamic State militants have deployed suicide car bombs and fired mortar rounds to slow the advance of Iraqi troops outside a key town near the militant-held city of Mosul.
An officer source from the 9th Division told the Associated Press on Wednesday his troops were about a kilometre from Hamdaniyah, an historically Christian town also known as Bakhdida.
Since Tuesday, IS has sent 12 car bombs, all of which were blown up before reaching their targets, he said according to the news agency.
Iraqi troops suffered a small number of casualties from the mortar rounds, the officer added.
Iraq launched a massive operation on Monday to retake Mosul, the country's second largest city and the extremist group's biggest urban bastion.
The operation is the largest launched by the Iraqi army since the 2003 US-led invasion.
About 25,000 troops, including Sunni tribal fighters, Kurdish forces known as the peshmerga and state-sanctioned Shi'ite militias known as the Popular Mobilization Units are approaching the city from different directions.
The participation of the Shi'Ite militias in the operation to retake the mainly Sunni Mosul has raised concerns that the campaign could inflame sectarian tensions. Rights groups have accused the Shi'ite militias of abuses in past campaigns against IS-held areas.
In a bid to alleviate those concerns, Shi'ite militia leaders on Tuesday announced they would only focus on capturing the mostly Shi'ite town of Tal Afar to the west of Mosul and not enter the city itself.