Lebanon and Syria are cracking down on Palestinian factions that for decades have had an armed presence in both countries and which on some occasions were used to plan and launch attacks against Israel.

The crackdown comes as Syria's new rulers under Islamist group Hayat Tahrir al-Sham are pursuing officials of the former government under Bashar Assad, including those in the ousted president's web of security agencies. Syria's most prominent Palestinian factions were key allies of the Assad dynasty in both war and peace time and closely cooperated on security matters.