The Central Syria campaign, known as "Operation Khuzam", or "Lavender", was a large-scale military operation of the Syrian Arab Army (SAA) against the Islamic State (IS) during the Syrian Civil War. Its goal was to capture the strategic oil town of Al-Sukhnah, and besiege and capture 11,000 square kilometers of ISIL territory in central Syria, after which the Syrian Army would advance towards Deir ez-Zor, and lift the three-year ISIL siege of the government's enclave in the city. Afterwards, the Syrian Arab Army advanced towards the Islamic State's then-capital of Mayadin.
The campaign was concurrent with the Raqqa campaign conducted by the Syrian Democratic Forces (SDF) against the Islamic State's former capital city and stronghold in Syria, Raqqa. In addition, the SDF launched their own offensive in mid-September south along the Euphrates River, after Syrian government forces reached Deir ez-Zor city.
The campaign
Syrian Army push into southern of the Raqqa Governorate
On 14 July 2017, the Syrian Army launched an offensive in the south of Raqqa province, advancing south of the town of Resafa and coming within 70 kilometers of Sukhnah after reaching the administrative border of Homs province. Between 15 and 16 July, a string of oil wells and gas fields was captured by the military. By 18 July, government forces pushed ISIL out of the western and southwestern parts of Raqqa province, while also reaching the outskirts of the Bishri Mountains, an ISIL stronghold.
With the start of the Syrian Government's push, the Russian Air Force launched a large-scale aerial campaign against ISIL in Raqqa and Homs provinces. An ISIL command-and-control center in Deir ez-Zor, targets along the Homs-Deir ez-Zor highway and positions near Sukhnah were reportedly hit.
Meanwhile, on 16 July, ISIL repelled an assault by the Syrian Army on the Hamimah area on the provincial border of Homs and Deir ez-Zor, killing a dozen soldiers and injuring or capturing 28 more. The captured soldiers were later reportedly decapitated. ISIL captured a tank and ammunition. Three days later, an ISIL raid on the administrative border overran an Army encampment before withdrawing. Concurrently, heavy fighting also erupted in Hama province. By 19 July, these clashes left 40 pro-government fighters, including two brigadier generals, and 29 militants dead.
On 21 July, the Syrian Army advanced between 30 and 35 kilometers east of Resafa. Four days later, major advances by government forces in the southeast of Raqqa reduced ISIL's control of the province to 10 percent. At this point, the Army was nine kilometers from the administrative border of Deir ez-Zor province. The Army was also making gains along the western bank of the Euphrates river. By the end of the day, they were six kilometers from the town of Maadan, located on the southern bank of the river, and the Deir ez-Zor provincial border.
Syrian Army advance along the Euphrates and capture of Sukhnah
Meanwhile, on 23 July, the Syrian Army's 5th Corps in the eastern part of Homs province launched an operation towards Sukhnah and the next day reportedly broke through ISIL's defense line before the town. On 25 July, massive Army reinforcements were arriving east of Palmyra for the upcoming assault on Sukhnah, following the implementation of a Russia/US-brokered ceasefire with the rebel FSA in the southwestern Badia region, where government forces had been conducting a two-month campaign. At the same time, Syrian Army troops advanced west of the Shaer gas field in the eastern countryside of Homs.
Elsewhere, on 25 July, the Syrian Army, backed up by Palestinian Al-Quds Brigade and local fighters, resumed their assault on the ISIL-held town of Qualib al-Thor in the eastern countryside of Hama Province. In the days before the resumption of Army operations in eastern Hama, the Russian Air Force conducted multiple strikes against ISIL.
On 26 July, ISIL conducted a counterattack against Syrian Army troops in an attempt to maintain its foothold in Raqqa province and defend Maadan. In the evening of that day, the Syrian Army captured the last hills eight kilometers southwest of Sukhnah, imposing fire control over the town. Several hours later, the Syrian Army started its attack on Sukhnah, quickly reaching its outskirts after a seven-kilometer advance and entering it from the west and south, according to military sources. According to the pro-opposition activist group the SOHR, government forces were still five kilometers from the town.
On 27 July, Syrian Army troops advanced to within four kilometers of Maadan, crossing the provincial boundary between Raqqa and Deir ez-Zor for the first time from the west.
Two days later, ISIL militants conducted an early-dawn raid against Syrian Army positions in the western countryside of Raqqa, forcing the Army to retreat. Soon after, Syrian Army troops regrouped and launched a counter-attack, pushing back the ISIL militants who withdrew with captured weapons and ammunition. Meanwhile, the Syrian Army entered the southwestern part of Sukhnah, while ISIL fighters started withdrawing from the town. Concurrently, the Syrian Army's Tiger Forces special unit redeployed from Raqqa province to eastern Hama for the upcoming offensive east of the town of Salamiyah. The same day, a large artillery bombardment of ISIL positions was conducted by Syrian Army and allied troops in the eastern Hama countryside in addition to airstrikes.
Late on 29 July, ISIL conducted a counterattack against the Syrian Army near the towns of Ghan Al-‘Ali and Shinan, pushing them back and cutting off their supply line to Ghan Al-‘Ali, as well as trapping a number of soldiers. 43 soldiers were killed and 65 wounded during the ISIL assault which included more than 10 suicide-bombers. The following day, the Syrian Army and tribal fighters regrouped and conducted a successful counter-attack, freeing the troops that were cut off. They then proceeded to advance into Ghan Al-‘Ali, eventually capturing the town, as well as several villages to the west of it. Syrian journalist Khaled Al-Khatib, who was working for the Russia Today television network, was killed when his vehicle was struck by an ISIL anti-tank missile in eastern Homs. By 31 July, Syrian Army forces advanced deep into the desert, coming within 40 kilometers of Deir ez-Zor city.
On 2 August, it was reported that the Syrian Army was only 700 meters from Sukhnah. The next day, after fierce street clashes, they had taken control of 20% of the town. Two days later, on 5 August, the Syrian Army took complete control of Sukhnah. A surprise ISIL raid near al-Tanf on 7 August led to the capture and subsequent execution of Mohsen Hojaji, an IRGC advisor. An image taken of Hojaji's last moments became iconic in Iran, and he became widely regarded as a nationally acclaimed "martyr" in the war against ISIL.
ISIL collapse and siege in Hama and Homs
On 9 August, as the Syrian Army advanced within four kilometers of Maadan in Raqqa province, ISIL conducted a large-scale assault in the east of Homs province near the strategic T-2 Pumping Station. Militants attacked Army positions in the Humaymah area, resulting in several hours of fierce fighting. The attack was eventually repelled, with the Army claiming more than 80 ISIL militants were killed, while they themselves lost 22 soldiers. In contrast, the SOHR reported the deaths of 32 Syrian Army soldiers and at least 35 ISIL militants. The ISIL attack took place on a 125 kilometer front.
Following a night-time operation late on 11 August, Syrian Army paratroopers, who landed behind ISIL's lines, captured two towns and 12 kilometers of desert in the southeast of Raqqa province. 25 ISIL militants and six Army commandos were killed during the operation.
Meanwhile, the Syrian government's Qalamoun Shield Forces, alongside the 5th Legion, also made a push towards ISIL's stronghold of Uqayribat in the eastern countryside of Hama, capturing several positions east of the village of Salba.
On 16 August, the Syrian Army made a push north of Al-Shaer mountains, overrunning ISIL positions in almost half a dozen areas, as other units progressed southwards from Ithriya and captured several hilltops. The next day, the Syrian Army's Tiger Forces suspended an offensive in the southeast of Raqqa Governorate in order to focus their efforts on the eastern Hama and Homs countrysides. This effort resulted in a myriad of military units storming arid, mountainous and sparsely inhabited, but oil and gas-rich ISIL-held areas in Central Syria from multiple directions, and the capture of more than half a dozen locations, including several of the oil and gas fields. During the same day, the 800th Regiment of the Republican Guard advanced 15 km north of Al-Sukhnah, capturing a checkpoint. ISIL fighters were left completely encircled between 50 and 100 villages in eastern Hama and Homs governorates on 18 August, as one group of Syrian Army troops advanced north of Al-Shaer mountains eventually linking up with recently redeployed Tiger Forces which pushed southwards from Ithriya. A smaller ISIL enclave formed south of the Ithriya-Zakia highway.
Elsewhere, Syrian Army forces captured southern and central parts of Humaymah village in the eastern Homs Province, after securing several hilltops near it the previous day. The village was completely secured on 21 August; however, ISIL launched a counter-attack on it hours later.
Between 23 and 24 August, the Army made advances northwest and west of Al-Sukhnah, with forces advancing north of the town and those advancing from Raqqa linking up and thus besieging a second large ISIL pocket in central Syria. Two days later, the pocket was cleared with the Army capturing an area of 2,000 square kilometers (772 square miles) between Sukhnah and Sha'er to the west.
ISIL counterattacks
During the evening of 23 August, ISIL forces in the western pocket attacked the Ithriyah-Salamiyah road in order to cut the Syrian government's main supply line to Aleppo, capturing two checkpoints south of the road (one of which was subsequently retaken by the Syrian Army and the National Defence Forces). At the same time, the rebel group Hay'at Tahrir al-Sham alongside Free Syrian Army shelled the supply line from the north; according to al-Masdar News, the ISIL attack was coordinated with the rebel groups. The next day, ISIL forces launched a large-scale operation west of Maadan alongside the western bank of the Euphrates, capturing seven villages from the Syrian Army and allied tribal fighters. Overall, government forces were pushed back 30 kilometers from the western outskirts of Maadan.
On 25 August, the Syrian Army stalled the ISIL assault against the Aleppo supply line and launched a counterattack, capturing three villages and putting themselves nine kilometers away from the ISIL stronghold at Uqayribat. The next day, the Tiger Forces troops also recaptured territory west of Maadan, but ISIL once again recaptured those same villages on 29 August.
Breaking of the siege of Deir ez-Zor city
On 27 August, the Syrian Army launched a major offensive along the Sukhna-Deir ez-Zor highway, advancing to positions 66 kilometers from Deir ez-Zor city by 29 August. On 31 August, the Syrian Army's Tiger Forces established full control over the strategic mountain of Bishiri, west of Deir ez-Zor. The offensive was accompanied by heavy Russian airstrikes on ISIL positions. They also captured the town of Haribshah. At this point, Syrian Army troops were 50 kilometers from Deir ez-Zor. By 2 September, the Syrian Army's Tiger Forces and 5th Corps alongside the Iran-backed Afghan Shia militia Liwa Fatemiyoun advanced from mount Bishiri towards Tal Al-Abd, Jabal Nazerat, Jabal Nairaman, and Jabal Admah, resulting in the capture of those hilltops and placing the Syrian Army within 25 km (16 mi) of lifting the siege imposed by ISIL for years on Deir ez-Zor city and within 16 km of village of al-Shulah, located southwest of the city. The next day, the Tiger Forces progressed further eastwards, coming within 18 km of Deir ez-Zor, capturing some minor hills in the desert and later in the day advancing towards al-Shulah and imposing fire control over the village from the north by securing Mount Neerman.
By 4 September, Syrian Army troops were within three kilometers of Deir ez-Zor, as ISIL sent reinforcements from Mayadin. The 5th Corps alongside the 18th Reserve Division captured the town of Kabajib during midday and later in the day captured the town of al-Shulah alongside the Tiger Forces.
The siege of the city was broken on 5 September 2017, at around 2 P.M. local time, when Syrian Army troops met the 137th Brigade on the western outskirts of the city.