On 19 February 2018, heavy clashes erupted between the newly established Syrian Liberation Front, which consists of Ahrar al-Sham and the Nour al-Din al-Zenki Movement, backed by the Suqour al-Sham Brigades, and Hay'at Tahrir al-Sham (HTS) in the western Aleppo Governorate. The conflict soon spread to the Idlib Governorate and the SLF captured several towns from HTS. A ceasefire between the two groups was reached on 24 April 2018. Fighting again resumed on 1 January 2019, ending with a total HTS military victory on 9 January.

Background

Tahrir al-Sham was formed by five Salafi rebel groups in Syria, including the al-Nusra Front and the Nour al-Din al-Zenki Movement, on 28 January 2017. During clashes between Tahrir al-Sham and Ahrar al-Sham, however, Nour al-Din al-Zenki refused to fight Ahrar al-Sham and defected from HTS. Violent clashes then erupted between Zenki and HTS in western Aleppo and northern Idlib between August and November 2017.

On 18 February 2018, Ahrar al-Sham and the Nour al-Din al-Zenki Movement announced a merger which established the Syrian Liberation Front. According to Sam Heller of the International Crisis Group, the formation of the Syrian Liberation Front was an attempt by Ahrar al-Sham and the Zenki Movement to create a "counterweight" against the dominance of Tahrir al-Sham in northwestern Syria. HTS reportedly prepared to attack Zenki prior to the merger.

Hay'at Tahrir al-Sham released a statement condemning Nour al-Din al-Zenki Movement and calling them 'aggressors' and liars about their willingness to resolve inter-rebel disputes in a Sharia court as well as calling them traitors, the statement also said this is part of a long series of conflicts with the Zenki movement and listed several incidents of times the Zenki movement acted against Tahrir al-Sham. Allegations included recruiting former Syrian Democratic Forces and YPG fighters to fight Tahrir al-Sham as well as attacks on bases belonging to Tahrir al-Sham. The statement also said that the Zenki movement planted IEDs and attempted to assassinate Tahrir Al-Sham members via this method, and that they are responsible for killing a Tahrir Al-Sham official named Abu Ayman Al-Masri after attacking a court house, a child, and a teacher from a religious college. The statement also said that the Zenki movement is being hypocritical regarding affairs in Idlib and the siege in East Ghouta by not sending fighters to Ghouta but rather deploying them to attack Tahrir al-Sham, they also condemned the Zenki movement for their support of de-escalation zones. Ahrar al-Sham also released a statement about their support for the Nour al-Din al-Zenki Movement and plans to expel Tahrir al-Sham from the area. The Nour al-Din al-Zenki Movement denied the claims made by HTS such as assisting YPG fighters in fighting HTS, as well as the claims about killing HTS members, with the group's spokesman stating the deaths occurred as a result of mistaken identities and confusion over whom the individuals killed actually were.Archived at Ghostarchive and the Wayback Machine:

Observers have said that the conflict is possibly being used by Turkey as an opportunity to expand influence over the area with groups aligned with Turkish interests in the area whilst liquidating hard-line groups such as HTS and Al-Qaeda.

Conflict First phase The conflict was triggered by the assassination of HTS commander Abu Ayman al-Masri on 16 February 2018, by Nour al-Din al-Zenki. The commander's wife was also wounded during the attack that killed him.

February

On 19 February 2018, a day after the Syrian Liberation Front was established, clashes erupted between the SLF and HTS in western Aleppo and northern Idlib. By 21 February, the SLF, with support from Suqour al-Sham, captured the city of Maarrat al-Nu'man, the towns of Ariha and Tramla, and the Wadi Deif military base near Maarrat al-Nu'man following HTS withdrawal. Meanwhile, in western Aleppo, HTS captured the villages of Kafr Laha, Basratun, Uwayjil and Taqad from the SLF.On social media, both groups accused each other of spreading fake news. HTS's official media outlet claimed on Telegram that "There are no problems between us and Ahrar al-Sham", and that Ahrar al-Sham fighters assisting the Nour al-Din al-Zenki Movement are "nothing more than individuals whose motivations are clear." This was said despite Ahrar al-Sham as a whole merging with the Nour al-Din al-Zenki Movement in forming the Syrian Liberation Front.

On 20 February the Syrian Liberation Front accused Tahrir al-Sham of capturing its members at checkpoints.

On 24 February, Hassan Soufan, general commander of the Syrian Liberation Front, called on the Sham Legion, who did not comment on the clashes, to side with the SLF against HTS.

During a brief battle on 26 February, mere hours after the loss of Darat Izza to the SLF, HTS reportedly captured the largest base of Ahrar al-Sham, Khirbet Bantanta Military Camp, located in northern Idlib province, thus securing a large stash of weaponry, including 20 tanks, towed artillery pieces, multiple rocket launchers, self-propelled guns and infantry fighting vehicles.

On 27 February, HTS withdrew from the city of Khan Shaykhun, and was expelled from western Aleppo, although it repelled the SLF advance on al-Dana. During the last day of February, HTS launched a large-scale counter-offensive, capturing settlements of Kafr Losen, Aqrabat, Deir Hassan, and Qah, as well as attacking the town of Atmeh.

HTS also handed over Morek to the Army of Glory and the SLF.

March

On 1 March, HTS released between 150 and 180 ISIL fighters captured during the Northwestern Syria campaign (October 2017–February 2018) by the Army of Victory and the Army of Glory to help in the fight against the SLF. Tahrir al-Sham recaptured Reef al-Muhandisin in the Aleppo Governorate, and a weapons depot there exploded. Syrian Civil Defense reported that they recovered bodies of eight individuals, while the reports claim that 20 were killed and eight wounded in the explosion.

On 2 March, Tahrir al-Sham advanced to the outskirts of the SLF stronghold of Atarib with an estimated 1,500 fighters and 30 tanks, along with other vehicles. However, Tahrir al-Sham fighters retreated from their staging positions after dozens of civilians demonstrated against the attack on Atarib. The head of Atarib's local council stated that they have reached an agreement with Tahrir al-Sham, which stated that the group will not enter Atarib. Multiple factions operating in Atarib, including the Atarib Martyrs Brigade, the Sham Legion, and Ahrar al-Sham, formed a unified military formation named the Revolutionaries of Atarib, consisting of over a thousand of fighters. The new formation stated that its goal is to protect Atarib from any aggressor. In Idlib, Abdullah al-Muhaysini and Musallah al-Olayan announced the formation of the Aba Union for foreign jihadist fighters to remain focused on fighting the Syrian government and not get involved in the infighting while still remaining in their respective factions.

The newly formed al-Qaeda faction Guardians of Religion Organization, specifically, Jaysh al-Sahel, threatened to engage the SLF if they attack certain villages.

As Atarib was surrounded on all sides by HTS, HTS has also announced plans to take Darat Izza and the Aleppo suburbs by force. The next day, the SLF took control of three in northern Aleppo and northwest Idlib, near Afrin.Image twimg.com Hussam Atrash the head of the SLF political bureau posted on Twitter threats of further violence against HTS. Several tribal forces are to be deployed to Idlib from Turkey after clan leaders in Urfa had a meeting with Turkish President Recep Tayyip Erdogan to discuss the framework and development of a council. The tribal fighters are being sent to Idlib on an unspecified date to support the Turkish military operation in Afrin in an interview a representative from the tribal fighters was asked about the situation in Idlib to which he said "we were asked to be ready to go there (Idlib)" he added, "If there is an internal order to fight HTS, we will participate".

On 3 March, the SLF (specifically the Nour al-Din al-Zenki) took advantage of HTS forces being off-balance. Attacked west of Kafr Nabl, the SLF captured three towns along a road, further isolating HTS garrisons in southern Idlib governorate. A media channel linked to SLF and Suqour al-Sham claimed the killing of 3 HTS commanders in Jabal Zawiya.

On 4 March, HTS launched a large-scale counter-offensive in Idlib and Aleppo, reportedly recapturing 50 towns and villages. During the HTS counter offensive SLF destroyed 3 tanks and 1 BMP while damaging 2 tanks using TOW missiles.Image liveuamap.comImage liveuamap.com Tahrir al-Sham captured Taqad and Saadiyah villages in western Aleppo from SLF. SLF stated that they destroyed 6 tanks from Tahrir al-Sham during the past two days in Taqad and Saadiyah. Clashes between the two in Shamiku village reportedly killed three and wounded three civilians.

On 7 March, Tahrir al-Sham captured settlements of Kafr Naha, al-Sa’adiyah and A’jil from SLF in the Aleppo Governorate, as well as housing complexes of al-Arman, al-Fursan and al-Rahal.

On 8 March, reports emerged Tahrir al-Sham released 50 Jund al-Aqsa members.

On 11 March, fighting resumed and several SLF members surrendered to HTS.

On 17 March, Faylaq al-Sham mediated a ceasefire agreement between Tahrir al-Sham and the Syrian Liberation Front. The agreement includes release of prisoners on both sides, cessation of attacks, and opening of roads leading to the front lines with the Syrian Arab Army and its allies.

Second phase

March

On 19 March, two days after the cease fire agreement Ahrar al-Sham arrested a Tahrir al-Sham commander named Yusuf al-Abdullah as he was trying to flee areas under control of the Syrian Army in the Hama Governorate, he was reportedly trying to flee to Lebanon.

On 22 March, reports emerged that Tahrir al-Sham and SLF are expected to resume clashing soon, as the temporary ceasefire ended today as the parties were unable to successfully negotiate a truce. Suqour al-Sham blamed Hayat Tahrir al-Sham's leader, Abu Muhammad al-Jolani for the cease fire falling apart because he refused the SLF's proposals and demanded that SLF hands over localities they captured from Tahrir al-Sham.

On 23 March, Tahrir al-Sham clashed with SLF in the western part of the Aleppo Governorate, 100 people gathered to demonstrate against Tahrir al-Sham in Atarib near the headquarters of Tahrir al-Sham and they opened fire on the demonstrators injuring one while they shelled the 46th regiment base. On the same day unknown gunmen stormed the headquarters of the Sham Legion in Idlib killing four of their members there is evidence that suggests that Jund al-Aqsa is behind the attack which has cells and remnants active in Tahrir al-Sham, Guardians of the Religion organization, the Turkistan Islamic Party, as well as a new group consisting of 300 former members of the group called Ansar al-Tawhid. Turkish President Recep Tayyip Erdogan told US President Donald Trump and Russian President Vladimir Putin that after the military operation in Afrin is complete that his next goal is to take both Idlib and Manbij.