The Pakistan Air Force sent a group of its fighter pilots to engage the Israelis in combat during the 1967 Six-Day War and the 1973 Yom Kippur War, greatly bolstering the Palestinians who were suffering repeated defeats to the Israel Defense Forces. A Pakistani fighter pilot, Saiful Azam, had shot down at least four Israeli fighter planes during the Six-Day War. After the Yom Kippur War, Pakistan and the PLO signed an agreement for training PLO officers in Pakistani military institutions. During the 1982 Israel-Lebanon War, irregular Pakistani volunteers served in the PLO and 50 were taken prisoner during the Siege of Beirut.