Judges 20:43 (KJV)

And when the men of Israel turned again, the men of Benjamin were amazed: for they saw that evil was come upon them.

Therefore they turned their backs before the men of Israel unto the way of the wilderness; but the battle overtook them; and them which came out of the cities they destroyed in the midst of them.

Thus they inclosed the Benjamites round about, and chased them, and trode them down with ease over against Gibeah toward the sunrising.

And there fell of Benjamin eighteen thousand men; all these were men of valour.

And they turned and fled toward the wilderness unto the rock of Rimmon: and they gleaned of them in the highways five thousand men; and pursued hard after them unto Gidom, and slew two thousand men of them.