The Islamic State group has killed 27 members of a pro-government paramilitary group in an ambush north of Baghdad, the Hashed al-Shaabi force said.

"On Sunday evening, a unit of the Hashed al-Shaabi was ambushed by the Islamic State terrorist group in the Hawija region" about 300 kilometres (185 miles) north of Baghdad, it said in a statement.

"The attackers were dressed in military uniforms and during the fighting 27 of our heroes were martyred."