Dozens of young pro-Palestine protestors took over Barnard College again Wednesday afternoon, this time storming the school’s library center as they yelled chants and played musical instruments. Concealing themselves behind face masks,

The group Columbia Students for Justice in Palestine said the bomb threat was “manufactured by Barnard administrators” to clear the protest.

The women’s undergraduate college at Columbia University expelled two student activists. Now it has become mired in a messy debate about discipline.