Iraqi officials say a double bombing outside a Kurdish party office has killed at least 18 people and wounded more than 65 others.
Sunday's blasts, including a suicide attack, occurred near an office of President Jalal Talabani's Patriotic Union of Kurdistan (PUK) party, which is near a security forces building.
The second bomb went off as emergency workers came to the scene of the first blast.
There has been no claim of responsibility for the attack, which struck northeast of Baghdad in the town of Jalula in Diyala province.
Iraq is facing some of its worst violence in several years, with nearly 800 people killed in May alone, the highest monthly total of the year.
On Saturday, a series of car bombings killed nearly 60 people in the Iraqi capital, part of a day of violence that saw militants attack an Iraqi university.
The blasts in Baghdad targeted mainly Shi'ite areas, underscoring the sectarian violence that has been on the rise in Iraq.
Elsewhere, heavy fighting between militants and security forces raged a second day in the northern city of Mosul. Officials say 38 militants and 21 police officers died in the clashes.
In Iraq's western province of Anbar, gunmen attacked a university and took dozens of students and staff members hostage before security forces led an assault to retake the campus. The hostages were freed and taken by buses from the school.
Police say militants began the attack by killing three guards at the gate of Anbar University in the city of Ramadi. There are conflicting reports on other casualties and on whether security forces or militants remain in control of the university.
There has been no claim of responsibility for Saturday's assault in Ramadi, although the group called Islamic State of Iraq and the Levant has carried out many attacks in recent months.
The group remains in control of the city of Fallujah and parts of Ramadi, the provincial capital.
On Friday, the U.N. refugee agency said about 480,000 people have fled their homes since fighting escalated between Shi'ite-led government forces and Sunni rebels in Anbar early this year.