Hospital officials in Iraqi Kurdistan said 20 fighters, including peshmerga and Shi'ite volunteers, were killed in a battle with Islamic State militants for control of two towns.
At least 33 fighters were also wounded as Iraqi forces battled Sunday for control of Jalawla and Saadiya, north of Baghdad.
In retaking the towns in the Diyala province, Iraqi troops forced the Islamic State fighters from areas they had held for months and cleared a main road from the capital, Baghdad, to Iran.
Fighting continues, with some pockets of resistance outside the two towns, police officials said on Monday, adding that teams are working to defuse roadside bombs.
Also on Monday, the U.S. Central Command said U.S. and its allies had conducted two dozen airstrikes against Islamic State militants since Friday, launching nine strikes in Syria and 15 strikes in Iraq.
The U.S. military said in a statement that airstrikes near the Syrian towns of Kobani and Raqqa took out three Islamic State fighting positions, targeted several staging areas and hit one of its headquarter buildings.
In Iraq, the strikes hit targets near Mosul, Asad, Baghdad, Ramadi, Tal Afar and Hit, destroying checkpoints and various Islamic State fighter units, the statement said.
Car bomb in Baghdad
Meanwhile, a car bomb exploded in a crowded Shi'ite-majority area of Baghdad Monday, killing at least 9 people and wounding at least 20, security and medical officials said.
The blast in the Shaab area of northern Baghdad struck an area where minibuses gather near a market.
No one immediately claimed responsibility. But Baghdad has endured near-daily bombings for months, most of which have targeted Shi'ite areas and been blamed on the Islamic State group and other Sunni extremists.
Iraq's Prime Minister Haider al-Abadi met with Gen. Lloyd Austin, the head of U.S. Central Command, on Monday, Abadi's office said.
Abadi said Iraqi security forces are pressing ahead with efforts to "liberate" territories seized by the Islamic State group, adding officials are also working on "post-liberation" plans for the areas.
Iraq's Shi'ite-led government, backed by U.S.-led airstrikes, has been trying to push back the Islamic State group since it swept through mainly Sunni Muslim provinces of northern Iraq in June, meeting virtually no resistance.
Some material for this report came from Reuters, AFP and AP.