In 1982, after an attack on a senior Israeli diplomat by Lebanon-based Palestinian militants in Lebanon, Israel invaded Lebanon in a much larger scale in coordination with the Lebanese Christian militias, reaching Beirut and eventually resulting in ousting of the PLO headquarters in June that year. Low-level Palestinian insurgency in Lebanon continued in parallel with the consolidation of Shia militant organizations, but became a secondary concern to Israeli military and other Lebanese factions. With ousting of the PLO, the Lebanese Civil War gradually turned into a prolonged conflict, shifting from mainly PLO-Christian conflict into involvement of all Lebanese factions – whether Sunni, Shia, Druze, and Christians.