 In any case, the PLO refused to surrender. By mid-June, the IDF surrounded 6,000 to 9,000 alleged terrorists in West Beirut. The PLO was supported by foreign mercenaries, had tanks, anti-aircraft weapons, and surface-to-air missiles. Iran also dispatched 1,000 Revolutionary Guard troops to the Bakha Valley to join forces with Hussein Massawi, a breakaway commander from Nabi Beri's Shiite Amal forces,