ISTANBUL: The Syrian army and its allies are advancing across the eastern desert towards the Islamic State-controlled city of Tabqa, which lies adjacent to a military airbase and sits 40km west of IS's de facto capital of Raqqa.

The capture of Tabqa and its airbase would represent a symbolic victory for the regime two years after IS publicly massacred over a hundred of its soldiers there.

Syrian army forces including elite commando units (Suqur al-Sahraa, Nusur a-Zaubaa, Fauj Maghawir al-Bahr) began a campaign to capture Raqqa city last week. The first major stop is Tabqa, whose airport is “the most important goal before moving towards Raqqa city,” Jameel Atallah, a journalist with pro-regime daily al-Baath told Syria Direct Monday from Hama city where he communicates with military sources.

Tabqa sits on a strategic crossroads linking four provinces, as the Salamiya-Raqqa highway and the Aleppo-Deir e-Zor highway both pass through the city. Tabqa is adjacent to a military airport and the IS-controlled Revolution Dam, which is Syria's largest and provides the eastern part of the country with electricity.

Since the beginning of their campaign on June 2, regime forces have captured dozens of kilometers in the desert as they move northeast along the Ithriya-Tabqa road, taking a series of villages, hills, and strategic intersections. Ithriya, located 100km northeast of Hama city, is a regime base that sits on its last major supply route into Aleppo city.

The Syrian army has entered the administrative borders of Raqqa province for the first time since 2014, reported pro-regime Lebanese channel al-Mayadeen on Monday.

In light of its rapid military progress, “capturing the airport [in Tabqa] is only a matter of time,” said Atallah.

Islamic State fighters following capture of Tabqa airport in August 2014. Photo courtesy of Assawsana.

Syrian and Russian warplanes struck IS targets west and south of Tabqa on Monday as the army “continued its progress in the western Raqqa countryside,” reported pro-regime Al-Watan.

Timing and geography have aided the regime's recent advance as its campaign coincides with a push by the Syrian Democratic Forces, made up primarily of the Kurdish People's Protection Units (YPG), against IS in the northern Raqqa and northeast Aleppo countrysides.

The SDF launched an attack towards Raqqa city from Tel Abyad in late May, but has since shifted its military momentum westwards towards the IS-controlled city of Manbij in Aleppo.

The SDF has now made it to within 5km of Manbij, reported pan-Arab daily al-Hayat on Monday. Manbij is one of IS's largest strongholds in Aleppo province, and serves as an important waypoint on IS supply lines heading south from Turkey towards areas of their control in northern and eastern Syria.

“The Islamic State is focusing on stopping the Kurdish forces' assault on Manbij, and so the regime exploited their scattered forces to mount an attack on Tabqa,” Waleed a-Samra, commander with the Sultan Murad brigade in the northern Aleppo countryside that is fighting IS there, told Syria Direct on Monday.

Aside from the SDF's campaign, a lack of natural or man-made barriers in the Syrian desert is facilitating the mission of Russian warplanes instrumental in supporting the Syrian army's advance there, said a pro-opposition journalist based out of Tel Abyad along the Turkish border.

“IS will not benefit from the area's desert nature, like they did in Palmyra, because the land is flat not hilly like the area around Palmyra,” said Ahmed a-Raqawi, originally from Raqqa city.

“This makes it very difficult for IS to send car bombs towards the regime's forces, and makes it easier for Russian planes and helicopters to target the Islamic State,” he added.

A Syrian army victory at the Tabqa airbase would mark a reversal of its fortunes in Raqqa province since 2014, and deal a blow to IS's image of invincibility that the group has tried to project through affiliated media networks.

In August 2014, months after consolidating control over Raqqa city, Islamic State forces took the airport and stripped and paraded 160 captured regime soldiers through the desert before executing them in a highly publicized propaganda video, according to an investigative report conducted by Syria Direct in December 2014.

IS hung a number of the decapitated soldiers' heads around Raqqa city, and widely broadcast images of the military hardware and planes that they captured in the assault on the Tabqa airbase.