ERBIL, Kurdistan Region – Iraq’s Shiite militia crossed the border into Syria during clashes with ISIS in the Euphrates River valley, a conflict monitor reported. 

Fighters of Iraq’s Popular Mobilization Forces (PMF), also known as the Hashd al-Shaabi, crossed the border at al-Qaim and were fighting ISIS in the al-Hiri area, the UK-based Syrian Observatory for Human Rights reported on Saturday. 

Al-Hiri is located in the countryside east of the Syrian city of al-Boukamal, the last major urban centre still in ISIS hands. 

After exchange of artillery, ISIS pushed the Iraqi forces back across the border, the Observatory stated. 

A spokesperson for one group within the Hashd al-Shaabi confirmed to The Associated Press that they had clashed with ISIS in the border area, but denied they had crossed into Syria. 

Jaafar al-Husseini of the Kataeb Hezbollah said his forces fired rockets into Syria from al-Qaim on the Iraqi side of the border. The Iraqi army and Hashd al-Shaabi took control of al-Qaim from ISIS on Friday. 

Husseini confirmed that Iraqi militias are already present inside Syria among Iranian-backed militias fighting side-by-side with Syrian government forces and he added that the Shiite militias will take part in securing a route from Iran to Lebanon. 

“We can say after liberating the borders that we have foiled the US project on the Iraq and Syrian borders,” he told The Associated Press. 

The United States is concerned that Tehran is looking to build a so-called Shiite Crescent connecting Iran with Lebanon via Iraq and Syria.