The source told Aswat al-Iraq news agency that the bomb had been stuck to the officer's vehicle and went off in the al-Majmouaa al-Thaqafiya region of Nineveh province, 400 km north of Baghdad.

Separately, one civilian was killed and two injured in a bomb attack near the northern city of Khanaqin, according to a security source.

The bombing took place near a car in Imam Wes region in al-Saadiya district, south of Khanaqin, Aswat al-Iraq reported.

Four civilians were killed when an explosive device went off near their vehicle in southern city of Karbala, a government source was quoted by Yaqen.net as saying.