Additional Palestinian refugees arrived after the 1967 Arab–Israeli War. Following their defeat in the Jordanian civil war, thousands of Palestinian militiamen regrouped in Lebanon, led by Yasser Arafat's Palestine Liberation Organization, with the intention of replicating the modus operandi of attacking Israel from a politically and militarily weak neighbour. Starting in 1968, Palestinian militants of various affiliations began to use southern Lebanon as a launching pad for attacks on Israel. Two of these attacks led to a watershed event in Lebanon's inchoate civil war. In July 1968, a faction of George Habash's Popular Front for the Liberation of Palestine (PFLP) hijacked an Israeli El Al civilian plane en route to Algiers; in December, two PFLP gunmen shot at an El Al plane in Athens, resulting in the death of an Israeli.