A series of blasts outside Shiite prayer halls killed four people and wounded 19 others on Friday in the northern Iraqi city of Kirkuk, police and medical sources said.
The deadliest blast took place in a car park outside the Mustafa prayer hall, or husseiniya, in the city's southwest, where a car bomb killed four worshippers and wounded 15 others after they had finished prayers.
Three roadside bombs near the Zahraa husseiniya in west Kirkuk wounded four people, while a roadside bomb near the Jaafar al-Sadeq husseiniya in the city's south caused no casualties.
Islamic State jihadists who overran swathes of northern and western Iraq last month have not taken Kirkuk.
Kurdish peshmerga forces moved in during the chaos but bombings and shootings are still common.
The Islamic State considers Shiite muslims heretics.