At least nine Iraqi federal policemen were killed on Sunday after a bomb struck their convoy southwest of the oil-rich city of Kirkuk, two security sources told Reuters.
The blast took place near the village of Safra, which lies about 30 km (20 miles) southwest of Kirkuk, said the source, adding that two other policemen were critically wounded.
Iraqi Prime Minister Mohammed Shia al-Sudani has ordered a hunt for the "terrorist elements" who carried out the attack, dispatching the federal police commander to the area for further investigation, his office said in a statement.
There was no immediate claim of responsibility, but Islamic State militants are active in the area. Iraq declared victory over the group, which once held large swathes of the country, in December 2017.
Iraqi police officers said Islamic State militants were involved in the attack, using roadside bombs to target the police force which was patrolling the area.
Despite the defeat of the Islamic State militant group in 2017, remnants of the group switched to hit-and-run attacks against government forces in different parts of Iraq.