A huge mob of masked pro-terror rioters broke into an academic building at Columbia University and seized it early Tuesday — rebranding the iconic hall named after founding father Alexander Hamilton and draping it with a giant flag calling for "intifada."

Dozens stormed into Hamilton Hall and sealed themselves in shortly before 1 a.m. — with some using metal barricades, chairs and tables to block others from getting inside, footage posted on social media shows.    

One shocking video captured a hammer-wielding demonstrator smashing through a glass-paneled door and placing what appeared to be a bike lock around its handles.