Iraqi police say a suicide car bomber has rammed his vehicle into an Iraqi army checkpoint north of Baghdad, killing nine soldiers.
Police say 15 other people, including several civilians, were wounded in Thursday's attack in the town of Khalis in Diyala province.
Hours later, a car bomb killed six people in southern Baghdad.
In northern Iraq, three bombings in Zummar, near the city of Mosul killed three people.
Police say the blasts - involving two truck bombs and a man wearing explosives - were apparently aimed at Kurdish peshmerga forces and an office of the Kurdistan Democratic Party of Kurdish leader Massoud Barzani.
In other news, the U.S. military says coalition forces killed seven terrorists during separate operations in Baghdad's Sadr City and near the town of Taji.
The military says coalition forces believe the fighting in Taji also killed two women and two children who it says were put in harm's way by al-Qaida in Iraq.
Meanwhile, radical Shi'ite cleric Moqtada al-Sadr condemned the wall being built by U.S forces around a Sunni enclave in Baghdad that has been targeted by Shi'ite militias. He called the project sectarian and racist. Iraqi Prime Minister Nouri al-Maliki also has criticized the barrier.
Some information for this report was provided by AFP, AP and Reuters.