In Lebanon, Shia-Palestinian relations had been very tense since the late 1960s. After the multinational force withdrew from Beirut in February 1984, Amal and the PSP took control of west Beirut and Amal built a number of outposts around the camps (in Beirut but also in the south). On April 15, 1985, Amal and the PSP attacked the Al-Mourabitoun, the main Lebanese Sunni militia and the closest ally of the PLO in Lebanon.