'Bars' in the Bible

Thus saith Jehovah to me: Make thee bonds and bars, and put them upon thy neck;

Go, and tell Hananiah, saying, Thus saith Jehovah: Thou hast broken the bars of wood; but thou hast made in their stead bars of iron.

Arise, get you up unto a nation that is at ease, that dwelleth without care, saith Jehovah; that have neither gates nor bars, that dwell alone.

The mighty men of Babylon have forborne to fight, they remain in their strongholds; their might hath failed; they are become as women: her dwelling-places are set on fire; her bars are broken.