Ongoing mutual bombardment in the de-escalation zone, northwest Syria

Sporadic shelling continues in areas of the de-escalation zones in Idlib and Hama governorates, while members of Hayat Tahrir al-Sham (HTS) were assassinated by unknown persons.
Syrian opposition rebel groups have targeted the positions of the Syrian government with rocket-propelled grenades in the town of Madaya, south of Idlib, while the Syrian government shelling continued on Sunday targeting the towns of Maarat Harma and Hass in the southern countryside of Idlib, and on the contact points west of Abu al-Duhur, in eastern countryside of Idlib, and the axis of Kabanah in the eastern countryside of Latakia, according to the Syrian Observatory for Human Rights.
The Syrian army and the affiliated forces targeted with dozens of rocket-propelled grenades after Sunday midnight the areas of Heesh, Kafr Sijnah, Maarat Harma, Rakaya and Maar Zita in the southern countryside of Idlib, no casualties were reported.
On the other hand, two members of Hayat Tahrir al-Sham HTS (previously known as al-Qaeda’s affiliate Al-Nusra Front) on Saturday, were assassinated by unknown gunmen, at a military checkpoint in the northwestern countryside of Idlib.
Local media sources indicated that masked persons opened fire while riding a motorcycle, as their identity remains unknown.
Meanwhile, pro-Syrian opposition social media accounts suggested that the perpetrators could be Islamic State’s sleeper cells.
While HTS had arrested yesterday an imam of a mosque in the city of Harem, under accusations of links with the Islamic State group (ISIS).
As ISIS has already adopted several attacks which targeted HTS, and other Syrian armed opposition groups in the governorate of Idlib.