A famous Thanksgiving parade in New York City turned into a pro-Palestine demonstration ... with protestors disrupting the route and causing chaos before getting booted.

Groups of demonstrators glued their hands to 6th Avenue as the Macy's Thanksgiving Day Parade was coming through ... forcing NYPD to redirect floats and balloons.

The protestors, dressing in white jumpsuits drenched in fake blood, protested against "capitalism" and "genocide" in the Middle East ... chanting "Free Palestine."

Crowds tried drowning out the demonstrations with boos ... and cops ended up removing protestors from the parade route ... but not without delays.

Other demonstrators busted out a huge banner reading "Genocide Then. Genocide Now" as they protested in front of a McDonald's float.

NYPD tells TMZ ... several protestors were taken into custody.

As you know, tensions are high in the Big Apple in the wake of the Israel-Hamas war ... with Susan Sarandon attending a pro-Palestine protest and getting dropped from her Hollywood talent agency for her controversial speech.

Sarandon said Jewish people in America living in fear of antisemitism since the Hamas terror attacks last month are finding out what it feels like to be Muslim in America.