 The castles of Khaybar had tunnels and passages which in wartime enabled the besieged to reach water sources outside the castles.Between 16 to 18 Muslims and 93 Jews were killed.After the Muslim victory, Muhammad, concerned that Khaybar would remain desolate and would not continue supplying its agricultural produce to the Hejaz, signed an agreement with the Jews which allowed many of its inhabitants to remain on their lands, while requiring payment of half their crops to the conquerors.