ERBIL, Kurdistan Region – The Syrian regime continues to advance south of Raqqa towards the ISIS stronghold of Deir ez-Zur, gaining significant ground in recent days, according to reports. 

The Syrian army and allied militias took control from ISIS of the town of Ghanim al-Ali, located on the eastern edge of Raqqa province, the conflict monitor Syrian Observatory for Human Rights reported on Sunday. 

According to the Observatory, regime forces crossed the provincial border into Deir ez-Zur on Thursday. 

Syria’s state-run SANA news reported on Sunday that the army had clashed with ISIS militants in several places in Deir ez-Zur province, including in the city of the same name where an enclave of Syrian army forces holds a military base and a portion of the city. 

The Syrian army, backed by Russia, has advanced south of the Euphrates River and now has a more than 100 km-long frontier with the US-backed Syrian Democratic Forces (SDF) south of Raqqa. 

Tensions between the SDF and Syrian regime forces appear to have eased after the SDF and Russia exchanged threats following the US downing of a Syrian military jet near Raqqa in June. 

The US-led coalition stated at the time that the Syrian jet had bombed their allied forces south of Tabqa. The SDF issued a statement vowing to “use our legitimate right to defend our forces” if the regime continued to attack their positions in Raqqa. 

Russia warned the US against aggression towards Damascus “carried out under the cover of ‘fight against terrorism.’ ”

The Independent reported last week that the Syrian army, Russia, and Kurdish YPG, the leading force fighting under the SDF banner, had a secret coordination centre in the desert south of Raqqa in order to prevent “mistakes” between their forces. 

A Kurdish soldier told The Independent, “all of us are fighting in one campaign against Daesh [ISIS], and that is why we have this centre — and to avoid mistakes.”

The centre had been set up ten days earlier. 

According to coalition figures, the Euphrates River valley area stretching from Deir ez-Zur across the Iraq-Syria border now holds the greatest number of ISIS fighters, including many of the group’s leadership. 

Some 5,000 to 10,000 ISIS fighters are in the valley out of an estimated less than 20,000 of those remaining throughout Syria and Iraq, coalition spokesperson Col. Ryan Dillon told reporters last week.