Kurdish peshmerga forces have retaken three towns on the way to Iraq's largest dam after a series of US air strikes.
Officials told Al Jazeera that peshmerga forces captured Tel Skuf, about 15km east of the Mosul dam, from Islamic State fighters early on Sunday morning.
The town is one of several seized by the Islamic State - a group of self-declared jihadists who have captured large swaths of land in northern Iraq and neighbouring Syria.
Peshmerga forces have also retaken the towns of Sharafiya and Batnaya.
The AP news agency quoted an unnamed peshmerga commander as saying that his forces were retaking parts of the dam, although that report has not been confirmed by Al Jazeera.
Al Jazeera's Zeina Khodr, in Sharafiya, said: "US air strikes pushed Islamic State fighters back, but this is not going to be an easy fight," she said. "Now that the group knows it faces a threat from the skies, it is changing tactics on the ground."
The progress came after the US hit targets near Mosul and Erbil to push back the fighters, but the scope of the air strikes has been limited.
"The nine air strikes conducted thus far destroyed or damaged four armoured personnel carriers, seven armed vehicles, two Humvees and an armoured vehicle," the US said in a statement.
Kurdish forces have also been slowed down by explosive devices, including homemade bombs and landmines, placed by the Islamic State.
Al Jazeera's Jane Arraf, reporting from Erbil, the capital of the Kurdish autonomous region, said that while the US air attacks were able to hit infrastructure, they were ineffective in dislodging fighters around them.
In Pictures: The Kurdish frontline in Iraq
The Mosul dam, which is located on the Tigris and provides electricity to much of the region, fell under control of Islamic State fighters earlier this month.
Its operations in the area come amid the worst violence in Iraq since 2006-2007. The group controls large parts of the west and north of IraqThe Islamic State has also seized large parts of Syria as it tries to build a caliphate across several countries.
On Saturday, the Syrian Observatory for Human Rights said Islamic State fighters had killed about 700 members of a tribe in eastern Syria.
The monitoring group said the killings took place in several villages home to the Sheitat tribe in Deir Ezzor province. The Observatory said many of the victims were beheaded.