At least two members of an Iran-backed militia were killed and three others were wounded in clashes with alleged Islamic State (ISIS) fighters in the countryside of Deir ez-Zor, eastern Syria, a war monitor reported on Monday.

The UK-based Syrian Observatory for Human Rights (SOHR) stated that the pro-Iran militiamen were targeted by a group of unidentified assailants, presumed to be ISIS members, while returning from a military base in the Salihiya desert of the al-Bukamal countryside.

The wounded have been hospitalized and are receiving treatment, according to the monitor. All five militants are reported to be Syrian nationals.

In recent months, ISIS has escalated its attacks in Syria, particularly in the vast desert regions where the group capitalizes on the security vacuum to launch surprise assaults. In May, five pro-Iran fighters were killed by an improvised explosive device (IED), which was attributed to ISIS.

ISIS gained prominence and seized large territories in Iraq and Syria in 2014, declaring a so-called caliphate. Although the group was declared territorially defeated in 2019, it continues to pose a significant security threat through hit-and-run attacks, bombings, and abductions.

Since the beginning of the year, approximately 400 Syrian army soldiers and affiliated militia members have been killed in ISIS operations in the Syrian desert, including at least 35 pro-Iran fighters, according to the SOHR.

This latest incident underscores the persistent danger posed by ISIS in the region and highlights the ongoing instability in eastern Syria.