The Daraa offensive (March–April 2016) was a military operation of two groups allegedly affiliated with the Islamic State of Iraq and the Levant, the Yarmouk Martyrs Brigade and the Islamic Muthanna Movement, against Syrian opposition forces in the Daraa Governorate.
Background
The Muthanna Islamic Movement was accused of kidnappings of Daraa officials and FSA commanders, which the Movement denied. Several of the prisoners were freed by the Yarmouk Army later. Muthanna was also alleged to have cooperated with the Islamic State.
In midst of the Second Battle of Al-Shaykh Maskin on 23 January 2016, against the Syrian Armed Forces, conflict erupted between the Muthanna Movement and the Yarmouk Army after the Movement blocked the road leading to the town. The Syrian Army was able to capture the town two days later.
The offensive
The first major clashes already broke out a week before the offensive.
On 21 March 2016, the Yarmouk Martyrs Brigade and the Islamic Muthanna Movement, both of which were accused of being Islamic State of Iraq and the Levant affiliates, stormed the towns of Tasil and Adwan after several hours-long fierce battles with the al-Nusra Front, Ahrar ash-Sham and the Martyr Raed al-Masri Brigade of the Free Syrian Army. At least two important al-Nusra military commanders were killed during the clashes: Abu Salah al-Masalma, general commander of Daraa Governorate, and Abu Adham, commander of Tasil. After suffering many casualties, opposition forces were eventually forced to retreat to Nawa. ISIL fighters went on to execute a number of residents in the captured towns, and broadcast an appeal over the local mosques' loudspeakers for the rebels to choose between “allegiance, surrendering their arms, or staying home.” In response to the ISIL takeover, many Tasil residents fled into the countryside. Afterwards, the Yarmouk Martyrs Brigade erected earth mounds around Tasil in order to fortify the town against rebel counter-attacks, and advanced further along the main road from Tasil to Nawa. ISIL forces also began to besiege al-Nusra Front and Ahrar ash-Sham troops in the villages of Sahem al-Jolan and Heit al-Latin. Subsequently, large numbers of opposition reinforcements were sent to southwestern Daara in order to halt the ISIL incursions. On the same day, ISIL forces detonated a suicide car bomb in Kherab Shahen, and targeted Tel Jomo with heavy machine guns and mortars. However, while the Islamic Muthanna Movement's western main branch aligned itself with ISIL forces, its eastern branch in Daraa city pledged only to fight the government. Nevertheless, family members of al-Nusra leader Abu Salah al-Masalma attacked vehicles of the eastern branch after hearing of his death.
The next day, Islamic Muthanna Movement fighters blew up the bridge linking Jalin, their main base, and Muzayrib in order to hinder opposition reinforcements from attacking their core area. Rebel troops also unsuccessfully attempted to regain Adwan.
By 23 March, the Yarmouk Martyrs Brigade once again broke through rebel defenses, with Tafas and Muzayrib becoming contested. One Yarmouk Martyrs Brigade commander was killed during these battles. On the same day, al-Nusra Front and other Islamist rebel reinforcements entered Zayzoun, Tal Shehab and Sahem al-Golan, and launched a counterattack on Tasil. Around 100 isolated ISIL fighters, belonging to the al-Nusra splinter group "Ansar al-Aqsa", also entrenched themselves in Inkhil, in the northern part of Daraa Governorate. Although these ISIL fighters had already been in conflict with local rebel groups for some time, the Hamza Division, the Mujahideen of Hawran Brigades and al-Nusra expelled Ansar al-Aqsa from Inkhil, soon after the offensive's beginning.
The Yarmouk Martyrs Brigade continued its advance on 24 March, when it captured most of Saham al-Jawlan from the al-Nusra Front and Ahrar ash-Sham. Most of Ahrar ash-Sham's forces were killed or captured during the battle, with remainder fleeing the city. Nevertheless, pockets of rebel troops continued their resistance in the city. With Saham al-Jawlan mostly under their control, ISIL forces completely surrounded a large number of rebel troops in the nearby town of Hayt. Meanwhile, rebel forces managed to repel the attacks on Tafas and Muzayrib. The Yarmouk Martyrs Brigade also targeted Nawa with heavy artillery strikes, killing many civilians. In response to the ISIL offensive, several Southern Front units, among them the prominent Yarmouk Army, formed the "House of Justice" operations room to push ISIL out of the Daraa Governorate. In the night from the 24 to 25 March, ISIL launched an assault against Hayt.