The Islamic State militant group struck at Kurdish forces southwest of the Iraqi city of Kirkuk on Friday, while bombs in Baghdad killed at least 21 people, security and medical sources said.
Police in the northern province of Kirkuk said IS launched mortars and attacked positions of Kurdish peshmerga fighters in four districts southwest of Kirkuk City, Al-Jazeera reported.
Since surging across the Syrian border last summer, IS has frequently battled security forces in the south and west of Iraq, but attacks on the outskirts of Kurdish-controlled Kirkuk have been rare.
A peshmerga officer said his forces had recaptured the district of Mariam Bek, but said clashes were ongoing in Tal al-Ward, Maktab Khalid and Mullah Abdullah.
Medical sources said at least four Kurdish fighters were killed in the fighting, including senior commander Brigadier Sherko Fatih. At least 70 others were wounded.
More than 750 peshmerga have been killed in combat since IS overran their defenses in northern Iraq last summer, prompting US-led air strikes.
The Kurds have now regained most of the ground they lost in August. However, peshmerga commanders complain that they remain ill equipped compared to IS fighters, who plundered Iraqi arms depots when they overran Mosul in June.
Earlier on Friday, security sources said at least 18 people were killed when two bombs went off in Baghdad's Bab al-Sharqi district.
Three civilians were later killed and at least 10 others wounded in northwestern Baghdad when mortars landed in residential neighborhoods, police and medics said. It is not yet clear if IS carried out the Baghdad attacks.
