The PLO kept strictly to the cease-fire for nine months except for two retaliatory strikes in May and June 1982 after extensive Israeli provocation. During the same time, Israel carried out plenty of provocative actions in southern Lebanon, including the sinking of Lebanese fishing boats in Lebanese territorial waters, “training exercises” in southern Lebanon, repeated deployment of military forces at potential invasion routes and 2125 violations of Lebanese airspace and 652 violations of Lebanese territorial waters.
The military manoeuvres in southern Lebanon were described by the UN as "intensive, excessive, and provocative”.
On April 21 Israel broke the nine-month truce with a still more provocative action, bombing alleged PLO centers in coastal areas south of Beirut.

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