Hasnain Jafer says his time spent in Israeli custody was "harrowing".
Hamas says Mohammed Odeh was killed alongside his wife and two children in a strike on a residential building.
The detainees say they were slapped, hit, humiliated and even subjected to sexual violence, but Israel's prison service says the allegations are false.
France and Italy are among the countries that have criticised a video showing Itamar Ben-Gvir taunting dozens of activists detained at an Israeli port.
The Global Sumud Flotilla says commandos have intercepted more than 50 boats trying to breach the Gaza maritime blockade since Monday.
The Hague-based court declines to comment, saying applications for warrants are classified as secret.
The Fatah faction elects top decision makers, but ordinary Palestinians feel the party and its leader are out of touch.
Nickolay Mladenov also warns the current stalemate over Donald Trump's peace plan could lead to a permanent division of the territory.
Displaced teenagers Farah and Tala wanted to 'turn destruction into something useful'.
