Portland Police cleared the Portland State University library of demonstrators.
When officers entered the building, a large group of people ran from the front door of the building.
A van transporting suspects in custody was stopped by the crowd. Oregon State Police troopers helped clear a path, so the vans could leave.
Inside of the library police found makeshift weapons, ball bearings, paint filled balloons and homemade armor.
Activists returned Thursday evening pulling down fencing and removing items from dumpsters. Police returned around 7 p.m. to move the people away from the library.
In all, 30 people were arrested. Seven of them were PSU students.