A suicide bomb attack critically wounded a senior Iraqi police officer and killed two of his guards on Tuesday near the eastern city of Baquba, police said.
The blast came a day after bombers and suicide attackers killed at least 51 people, including 23 in two explosions in the nearby town of Muqdadiya.
Brigadier Qasim al-Anbuki, the local head of police intelligence, was leading a force to check tips about a suspected car bomb parked on a highway linking Baghdad to eastern Diyala province, where Baquba is located.
After reaching the site, a suicide car bomber detonated his vehicle near the officer's convoy, two police sources said. Three other officers were also wounded, they added.
There was no immediate claim of responsibility, but Islamic State militants controlling swathes of Iraq's north and west said they were behind Tuesday's blasts in Muqdadiya and earlier attacks at a Baghdad mall that killed 18 people.
The rise of Islamic State, an ultra hardline Sunni Muslim group, has exacerbated a long-running sectarian conflict in Iraq, mostly between Shi'ites and Sunnis.
Prime Minister Haider al-Abadi condemned the mall attack on Tuesday after visiting the site, calling it "a desperate attempt by terrorist gangs after our forces' victories in Ramadi and other areas".
The Iraqi government last month claimed victory against Islamic State in the western city of Ramadi, and has slowly pushed them back in other areas.