ERBIL, Kurdistan Region — Hashd al-Shaabi clashed with ISIS militants southwest of Kirkuk city on Sunday, resulting in the deaths of 27 Hashd fighters.

The Hashd al-Shaabi had been conducting anti-terror operations in the Hawija areas for a number of days, targeting reported sleeper cells in the area, the force detailed in a published statement on Monday. 
 
"Yesterday night, the force was ambushed by a terrorist group from the area disguised in military uniform, resulting in violent clashes lasting more than two hours,” the Hashd stated. 

Reinforcements arrived and were able to defeat the attackers, but 27 members of the Hashd were killed. 

ISIS militants opened fire on Hashd al-Shaabi fighters between villages of Sahdunia and Shahria in the sub-district of Riaz, 45 km southwest of Kirkuk, according to statements made by security forces to Iraqi media. This has led to heavy clashes between the two.

Ali Husseini, the spokesperson for Hashd, said his forces came under fire in a place in the area and added their forces together with the federal police besieged the location.

Iraqi Prime Minister Haider al-Abadi vowed to “prosecute and punish the perpetrators,” according to a statement from his office. 

“We are determined to eliminate these sleeper cells and terrorists, and I order the commanders of operations there to investigate the circumstances of the incident and take necessary proceedings in this regard," he said.

The fighting was near Shahria Bridge in the village of Sahdunia in Riaz sub-district between the Ali Akbar brigade of Hashd and ISIS militants. Earlier reports were that more than 27 Hashd fighters were missing or kidnapped in the clashes.

Riaz is in the Hawija pocket, an ISIS stronghold through the three-year conflict.

ISF and Iran-backed Hashd al-Shaabi paramilitaries took control of Kirkuk city and the province's major oil resources in October.

Kurdish officials and residents have complained of a deteriorating security situation in Kirkuk. Politics in the diverse province are in a stalemate as Kurds claim another Arabization.