According to Police official from Salah el-Din province, Islamic State elements opened fire on a trailer in which Hash Shaabi militiamen had been preparing a pre-dawn meal before the start of fasting hours.
The official said that the attack left all the 12 people inside the trailer dead. Meanwhile, they set the trailer on fire before fleeing the scene.
However, a manhunt had been launched to arrest them.
Iraq declared victory over Islamic State in December 2017, having retaken all the territory captured by the Sunni extremists in 2014 and 2015 with the help of a U.S-led alliance.
However, some remnants of the extremist group remained in the country.(dpa/NAN)