On 4 April, ISIL attacked areas around the city of al-Dumayr, northeast of Damascus, resulting in 250–300 cement plant workers being abducted from a factory by ISIL.[6] ISIL reportedly massacred 175 of them afterwards, while 75 escaped.[citation needed] Druze employees were murdered while non-minority Muslims were released.[7][8]
On 6 April, ISIL launched an attack on the Dumayr Airbase, outside the town, sending five car bombs and killing 12 Syrian soldiers.[9] The attack was repelled by the Syrian Army and the National Defence Forces.[10] Due to a partial ceasefire, the Syrian Armed Forces reportedly allowed some Jaysh al-Islam militants from Ghouta to cross into al-Dumayr in order to fight ISIL. The Syrian Air Force also hit ISIL targets in the front with the rebels.[1]
On 9 April, a new ISIL attack on the airport and power plant was reportedly repelled,[11] after which the airport was declared secured.[12]
On 11 April, a Syrian Air Force plane was shot down by ISIL near the airbase.[13] Two days later, yet another attack on the airbase was repelled, although Army checkpoints outside the base had sustained heavy damage.[14]
On 14 April, the Army launched a counter-attack, quickly recapturing several hilltops,[15] and by the following day, they had retaken control of the Khan Abu Shamat base and the Badia cement plant.[16][17] On 16 April, the military continued to advance and recaptured the Battalion 559 base, Al-Sini Factory, Al-Safa Station and the triangle Baghdad-Palmyra-Jordan checkpoint, ending the ISIL offensive.[18][19]