More than 45% of the pro-Palestinian protesters arrested at Columbia University and City College this week were “unaffiliated” with the schools, NYPD sources told the Daily News on Thursday, though it’s unclear how many of the demonstrators were so-called “outside agitators” involved in driving the recent tumult on the campuses.

New York Police Department officers entered campus through a gate near a school library and told people to disperse, yelling for them to exit from the premises. The NYPD had amassed outside the Manhattan campus earlier in the evening while saying they were awaiting word from Columbia officials to come to the school’s aid.