cbs's meg oliver reports. >> reporter: tension and concerns about safety continue to embroil columbia university. with classes remote only, some jewish students and faculty say the environment has only escalated. >> jewish students are petrified to go onto campus. >> reporter: for the past six days, hundreds of pro-palestinian demonstrators, including jewish students, have occupied the school's quad, demanding the school divest from companies funding israel. >> anti-semitism is a huge problem in the united states, but anti-zionism and anti-semitism are two very different things. >> reporter: late this afternoon, president biden denounced anti-semitism. >> i condemn the anti-semitic protests. that's why i've set up a program to deal with that. i also condemn those who don't understand what's going on with the palestinians. >> reporter: the protests have spread to multiple universities, including the university of michigan, m.i.t., nyu, and emerson college in boston. about 60 people have been arrested at yale since the start of the protests. orthodox jew sahar tartak, the editor in chie