That day, the armies of Egypt, Lebanon, Syria, Jordan and Iraq invaded what had just ceased to be the British Mandate, marking the beginning of the 1948 Arab–Israeli War. The nascent Israeli Defense Force repulsed the Arab nations from part of the occupied territories, thus extending its borders beyond the original UNSCOP partition. By December 1948, Israel controlled most of the portion of Mandate Palestine west of the Jordan River. The remainder of the Mandate consisted of Jordan, the area that came to be called the West Bank (controlled by Jordan), and the Gaza Strip (controlled by Egypt). Prior to and during this conflict, 713,000 Palestinian Arabs fled their original lands to become Palestinian refugees, in part due to a promise from Arab leaders that they would be able to return when the war had been won, and also in part due to attacks on Palestinian villages and towns by Israeli forces and Jewish militant groups. Many Palestinians fled from the areas that are now Israel as a response to massacres of Arab towns by militant Jewish organizations like the Irgun and the Lehi (group) (See Deir Yassin massacre). The War came to an end with the signing of the 1949 Armistice Agreements between Israel and each of its Arab neighbours.