Students haunted by ghostly figure
This is so much better than the excuses I used. From allAfrica.com:
THE head teacher of Mumbwenge Combined School, about five kilometres from Oshigambo in the Ohangwena Region, Helena Makili, says the "ghostly figure" that is tormenting learners at the school could cause learners to fail their examinations. She says the uninvited visits involving a paranormal figure at the school is tormenting students so much so that they are likely to perform poorly. According to her, not a single day passes without children being harassed by the mysterious and extremely sinister figure.