ِAMMAN: The Syrian Arab Army patrolled the streets of a former Islamic State refuge in Deir e-Zor province on Monday, searching for remaining fighters and explosives left behind after pro-regime forces scored a rapid victory in the desert city of Mayadeen  earlier this week, a pro-government journalist told Syria Direct on Monday.

In June, high-ranking Islamic State (IS) leaders and much of its operational command relocated to Mayadeen after US-backed forces moved into the militant group’s de facto capital of Raqqa city. Aside from being an IS command center, Mayadeen also served as a hub for stockpiling weapons and trafficking them to the frontlines.

On Saturday, Syrian government troops “completely” liberated Mayadeen, a spokesman for the Russian Defense Ministry told Russian state media. Victory in Mayadeen came quickly—less than a week and a half after the Syrian government launched an offensive to take the city on October 5.

That same day, Syrian government soldiers lit cigarettes and posed for pictures in the middle of Mayadeen. In one video released by Russian state media on Saturday, an older Syrian army officer stands in front of a weapons cache in a building near the Euphrates River in Mayadeen. Behind him, small arms, mortar rounds, artillery shells and ammunition lay in a pile reaching the ceiling.  

“This is the first time we’ve uncovered such a huge quantity of weapons,” the unnamed officer said in the video. “Most of the Islamic State’s weapons and ammo are here, in this area.”

The capture of Mayadeen is part of a wider regime offensive to drive IS from the province, where both US-backed Kurdish-majority forces and pro-government fighters continue to capture towns and villages previously controlled by the militant group in the Deir e-Zor countryside.

The Syrian regime is now expanding its offensive, consolidating its control over villages surrounding Mayadeen as it battles IS fighters 40km to the north in Deir e-Zor city, the provincial capital.

Last month, the Syrian government broke a three-year siege of its forces by IS in Deir e-Zor city. Since then, regime forces have continued to chip away at Islamic State-controlled neighborhoods and have crossed the Euphrates River to target IS positions on its eastern bank.

Pro-regime forces captured the town of al-Husayniya on Monday, roughly two kilometers north of Deir e-Zor city, pushing the frontlines on the eastern bank of the Euphrates farther north.

Amid the regime’s advances against IS in September, US-backed Kurdish-majority forces launched a major offensive east of Deir e-Zor’s provincial capital, expelling IS from villages and hamlets within 20km of the city, as well as taking control of several crucial oil fields formerly under the militant group’s control.

Today, the US-backed Syrian Democratic Forces (SDF) hold roughly half of eastern Deir e-Zor province, having reached the eastern bank of the Euphrates River north of Deir e-Zor city.

Hundreds of regime, Russian and coalition airstrikes have decimated the Islamic State’s forces, with surviving fighters abandoning their weapons and munitions as they flee south, deeper into Syria’s eastern desert near the Iraqi border.

On Monday, a spokesperson for the US Central Command (CENTCOM) told Syria Direct that the Islamic State now controls 13 percent of the territory it held two years ago.

The outskirts of Deir e-Zor city on September 24. Photo courtesy of AFP.

Islamic State leaders are “completely disconnected from the fighters on the ground,” the CENTCOM spokesman wrote in an email to Syria Direct. “We have degraded their industrial base, their financial system, communication networks and the system they use to bring [in] foreign fighters.”

The Islamic State maintains control of several population centers in the Deir e-Zor countryside, most notably al-Bukamal, a small city on the Euphrates River along the Iraqi border that formerly served as a major trade point between the two countries.

Though their campaigns are separate, the Syrian Arab Army and the American-backed SDF say they have the same goal: to drive out the Islamic State.

Abu Khawla, a Deir e-Zor native and spokesman for the US-backed Syrian Democratic Forces told Syria Direct that the SDF’s goal is to “fight IS and expel it from every inch of Deir e-Zor province.”

“We need to liberate the eastern bank of the Euphrates, along with al-Bukamal on the western bank,” Abu Khawla said. “We’re going to liberate the entire eastern countryside.”

IS controls large swaths of territory in southeast Deir e-Zor and in the eastern desert, Mustafa Bali, a second SDF spokesman told Syria Direct on Monday. This territory includes “less populated areas IS can use to hide in and to conceal weapons depots.”

Even as it appears that the battle for the east is nearing its end, Bali warned that the Islamic State would not disappear so easily.

“The next incarnation of IS in Syria will use sleeper cells and terror attacks,” Bali said. “The important thing is for us to be aware of Islamic State capabilities after it is no longer overtly present on the ground.”

There remains “much more to be done,” the SDF spokesman said.