The following is a timeline of the Syrian Civil War from September to December 2017. Information about aggregated casualty counts is found at Casualties of the Syrian Civil War.
September 2017
1 September Syrian Democratic Forces (SDF) seize full control of the Old City in Raqqa from the Islamic State (ISIL).
2 September The Russian Aerospace Forces report that they destroyed a large convoy of twelve ISIL trucks with ammunition and weapons in Deir ez-Zor Governorate. The British Ministry of Defense claimed that British troops had left Syria in late June 2017 and halted their FSA training program.Britain withdraws last of troops training Syrian rebels as world powers distance themselves from opposition, Daily Telegraph 2 September 2017
3 September Syrian Army (SAA) forces capture the city of Uqayribat from ISIL, the last stronghold of the group in the Hama Governorate.IS clashes with Syrian regime forces kill 150, AFP in Times of India 3 September 2017
5 September
The Syrian Army, aided by Iranian-backed militias, as well as by Russian advisers and Russian airstrikes, break the three-year siege of the city of Deir ez-Zor by ISIL by reaching the Brigade 137 desert base.A boost for Assad as the Syrian army makes gains against ISIS in eastern Syria, Washington Post 5 September 2017 In conjunction with the Deir ez-Zor offensive, Russian frigate Admiral Essen in the Mediterranean Sea launches cruise missiles at ISIL targets near Deir ez-Zor, killing many fighters an destroying command and communications posts, ammunition depots, and repair facilities for armored vehicles.
6 September The United Nations Commission of Inquiry on Syria issues its report on the April 2017 Khan Shaykhun chemical attack. They report that it was the gravest of 27 chemical attacks by the Assad government.Stephanie Nebehay "Syrian government forces used chemical weapons more than two dozen times - U.N." Reuters 6 September 2017 Staffan de Mistura, the U.N. special envoy for the Syrian conflict says that the Syrian opposition must accept that it has "failed to win the war", but also that the government "cannot announce victory".Syrian conflict: Opposition must face reality it lost war against, ABCSyrian opposition must accept it has not won the war: U.N., Reuters
7 September Israeli jets bomb a suspected chemical weapons depot near the city of Masyaf, Hama Governorate, killing at least two Syrian Army (SAA) soldiers.
9 September The SAA breaks the nine month-long siege of Deir ez-Zor Airport by ISIL. The Syrian Democratic Forces (SDF) announce an offensive against ISIL in the north of the Deir ez-Zor Governorate.
10 September
Syrian Democratic Forces claim they advanced 50km and reached an industrial zone miles to the east of Deir ez-Zor city as part of their offensive against ISIL in the northern and eastern parts of the Deir ez-Zor province, while pro-government forces regained full control of the highway from Deir ez-Zor to Damascus, putting SDF and pro-government forces within 15km of each other. Scott Lucas "Syria Daily: Pro-Assad and Kurdish-Led Forces Converge on ISIS in Deir ez-Zor City" EAWorldview September 11, 2017 At least 34 civilians, including nine children, are killed in a Russian air raid on Euphrates River ferries near Deir ez-Zor city, according to the Syrian Observatory on Human Rights (SOHR).Russian air raids kill 34 civilians near Deir Az Zor, Al-Jazeera, 10 September 2017
11 September Russian warplanes continue with their aerial campaign on the eastern province, with at least 19 civilians killed in an airstrike on the ISIL-held village of al-Khrayta, near Deir ez-Zor city on Monday, AFP reports. SOHR says that “Two sets of strikes 30 minutes apart hit civilians sheltering in tents along the Euphrates and boats on the river”.Syria army readies push into IS-held parts of Deir Ezzor AFP Hezbollah Leader Hassan Nasrallah declares that the ´Syrian war is won´.Hezbollah declares Syria victory, Russia says much of country won back, ReutersSyria Daily: Hezbollah — “We Have Won", EAWorldview September 13, 2017
13 September At Russia's request, US air forces allow a convoy carrying ISIL fighters to reach al-Mayadin in ISIL-held territory in eastern Syria after being bused from the Lebanese border as part of an evacuation agreement brokered by Hezbollah and the Syrian government.ISIS Convoy Reportedly Crosses Syria, at Russia's Request, NYT, 13 September 2017
14 September A US-led Coalition spokesman states that the Coalition-backed SDF forces will not go into Deir ez-Zor city, but will leave it clear to Russian and government forces.U.S.-backed forces not planning on entering Deir al-Zor city, Reuters, 14 September 2017
15 September
The representatives of Iran, Russia and Turkey reach an agreement for the implementation of a “de-escalation zone”, in the Idlib Governorate.Final de-escalation zones agreed on in Astana, Al-Jazeera Turkish government-linked Yeni Safak newspaper says in an unsourced report that the three countries plan to divide the Idlib region into three, with Turkish forces and opposition fighters in the northwest region bordering Turkey. The deal takes place amid pro-government media reports that "around 9,000 militants" from Jabhat Fateh al-Sham attempt to wrest control from other rebel groups.Astana deal: Russia, Iran and Turkey agree on final Safe Zone in Syria , Al-Masdar
Ahmad Abu Khawla, commander of the SDF's Deir ez-Zor Military Council, states that it will not allow Syrian government forces to cross the Euphrates.
16 September Russian aircraft reportedly bombs SDF positions on the eastern bank of the Euphrates, injuring six SDF fighters, according to US-led Coalition sources. Russia denies responsibility.Russia denies bombing US-backed Kurdish fighters in northern Syria as tensions rise, Al-Araby, 16 September 2017
17 September SAA troops seize a suburb of the city of Deir ez-Zor, cornering ISIL forces there with the intention of encircling them.
18 September SAA forces cross the Euphrates river in the Deir ez-Zor Governorate.First-seen footage of Syrian Army crossing the Euphrates River , Al-MasdarWith Russian cover .. The forces of the regime crosses to the eastern bank of the Euphrates River, Syria Observatory of Human Rights (In Arabic)
19 September Rebels led by HTS launch an offensive in Hama and Idlib against the government and its allies, code-named “Oh Servants of God, Be Steadfast”.Bombardment returns to rebel-held northwest as HTS aims to 'demolish, defeat' Astana ceasefire , Syria Direct, 19 September 2017
20 September Syrian Tiger Forces advance against ISIL in the northwest Deir ez-Zor Governorate as Syrian troops close in on southeast Raqqa Governorate, according to a military source close to the government; the towns of al-Tabni, al-Turayif, al-Buwytiyah, Khan Zahra and al-Masrab are captured from ISIL forces.Elite Syrian forces make massive advance up west Euphrates bank amid major ISIS collapse , Al-Masdar News
21 September Russian and Syrian warplanes launch airstrikes in the south of Idlib, killing three civilians and wounding several others. A prominent Syrian opposition activist, Orouba Barakat, and her journalist daughter, Hala Barakat, a US citizen, are found dead in their Istanbul apartment late Thursday.Syrian dissident and her American daughter killed in their Istanbul home, Washington Post, 22 September 2017
22 September The SOHR report an agreement between the Syrian Army forces and ISIL militants on the East Hama region. The truce includes the evacuation of ISIL members and their families out of the villages they control. This follows 18 days of clashes that have left over 305 ISIL fighters and 138 pro-government forces dead.
23 September There are multiple Russian airstrikes in Hama Governorate and Idlib Governorate, including the targeting of a Faylaq al-Sham headquarters in the area of Tal Mardiqh - killing over 50 fighters according to rebel sources and attacks on Khan Sheikhoun, Jisr al-Shaqour, Saraqeb and Kafr Sajna.Russia, Syria intensify bombing of rebel-held Idlib, witnesses, Reuters, 24 September 2017Tens of fighters are still missing under the rubble caused by airstrikes which killed 22 fighters, SOHR, 23/09/2017 The SDF captures the Conoco gas field, a major gas field in Deir ez-Zor Governorate, from ISIL..S.-Backed Forces Seize Syrian Gas Plant From Islamic State, Wall Street Journal, 25 September 2017Syria: SDF says it took Conoco gas field from ISIL, Al-Jazeera, 23 September 2017
24 September Syrian government media and SOHR report rebel shelling of President Assad's hometown Qardaha.Shelling on Syrian president's hometown kills 2, Associated Press, 25 September 2017 SOHR report heavy shelling and 40 deaths in the Idlib countryside.More casualties raise death toll of warplanes’ bombardment to about 40 since dawn of today in Jisr Al-Shughur city and Idlib countryside, SOHR, 25/09/2017 Russian lieutenant general, Valery Asapov, is killed by mortar fire from ISIL near Deir ez-Zor.
25 September The Syrian government reports that rebel shelling of Qardaha continue, while SOHR, Syria Civil Defence and other sources in rebel territories report major government and Russian airstrikes in Idlib governorate, with at least 37 people in the town of Jisr al-Shughour and nearby areas.Syria war: Russian air strikes in Idlib leave 37 civilians dead, observatory says, ABC News, 26 September 2017Air and rocket strikes continue for the eighth consecutive day targeting Hama and Idlib provinces and cause more destruction in the infrastructure, SOHR, 26 September 2017 Russia denied it had bombed any civilians.Russia denies it killed civilians in air strikes on Syria's Idlib, Reuters, 26 September SDF forces say Russian warplanes struck their positions in the Conoco gas field in Deir ez-Zor Governorate, killing one and wounding two, although Moscow denies the claims.U.S.-backed alliance says Russian jets struck its fighters in east Syria, Reuters, 25 September 2017US-backed forces say Russia attacked them in eastern Syria, AP, 25 September 2017
26 September
The Syrian government says it will consider allowing some autonomy for Kurdish regions.Syria to consider granting Kurds greater autonomy, Al-Jazeera, 26 September 2017
27 September Russia conducts airstrikes on the villages of Qaina and Yaqobia, killing a child and injuring 5 more. The city of al-Tamane'a is bombarded by five Russian warplanes with rockets, bombs and missiles wounding several and forcing others to flee.
28 September Russian President Vladimir Putin holds talks with Turkish President Recep Tayyip Erdogan in Ankara, Turkey to discuss the setup and monitoring of a combat-free zone in Syria.Putin, Erdogan Hold Talks on Missile Sale, Syria Cooperation, Bloomberg, 28 September 2017 ISIL releases audio of their leader, Abu Bakr al-Baghdadi urging his followers to attack against "crusaders and apostates".
October 2017 1 October The Islamic State seizes the town of Al-Qaryatain in the province of Homs in a surprise attack against government forces.
2 October At least 10 people are killed and 20 are injured in a twin suiciding bombing on a police station in the Al-Midan neighborhood in Damascus.
3 October ISIL releases a video of two Russian soldiers they claim to have captured. However, Russia denies that they are their soldiers.
4 October Suspected Russian fighter jets target rubber dinghies and family boats fleeing the town of Al-Ashara, killing at least 60 civilians. Russian defence minister Igor Konashenkov claims that ISIL have undertaken several attacks on Syrian cities through US-controlled areas.