school has sparked unroar and threats of violence. classes were cancelled for about 10,000 students. they say they have received thousands of calls and emails and threats of violence. >> reporter: the halls here were empty on friday. more than ten thousand students at 23 public schools were told to stay home until monday. they were taking measures after receiving tens of thousands of hostile emails over an arabic writing assignment. some phone calls were threatening and abusive. this is the sheet of paper that they were asked to copy for their world religions homework. it says god as moham ed is god's prophet. the symptoms are wider anti muslim sentiment being in political campaigns >> when we are being fed fear day in and day out, we act as human beings, we act out of that fear and we account irrationally. that's a symptom of a bigger problem because we're getting ready to choose the next president. this is an important policy decision that we are making and when we are literally judgment is impaired by this fear rhetoric, we are not