Secret Tunnel Discovered Under Brooklyn Synagogue Sparks Chaos

A massive secret tunnel was discovered under a historic Jewish synagogue in NYC -- and when the authorities tried to shut it down ... sheer chaos ensued from the guys using it.

Wild footage is circulating online showing a frenetic scene Monday at the Chabad-Lubavitch World Headquarters in Brooklyn's Crown Heights -- serving as the meeting location and place of worship for Orthodox Jews in that area ... and it all has to do with this hidden passage.

Long story short ... this underground enclosure leading into the synagogue was stumbled upon last month by civilians who reported hearing weird noises under their homes.

There's reports that a select group from this synagogue were using the tunnel to access a shuttered women's bathing area ... plus other areas in and around Brooklyn, it seems.

Anyway, leadership from this synagogue decided to shut this whole thing down -- bringing in construction crews to seal up the tunnel with cement ... but apparently, the fellas who'd been using were outraged and started rioting within their own holy institution, and cops came out.

That's where all these clips come in -- showing the Jewish clashing with cops, overturning furniture and seemingly trying to hunker down in their tunnel to avoid it being closed up.

At some point, someone went down into the tunnel itself and recorded a little walk-through -- and you can see these fellas made themselves at home ... draping their clothes all about.