Rebel groups in Idlib province have been sporadically fighting each other since early this year. Rebels have also accused the Islamic State militant group of carrying out attacks in the area. Idlib province is a major stronghold of rebels in Syria and is situated along the border with Turkey, one of the main backers of their rebellion against President Bashar al-Assad.
Large numbers of fighters, along with their relatives and many other civilians, have moved into the area under amnesty after surrendering to the army in other parts of Syria.