foreign student have to quite china before olympic starts

well i wanna discuss some thing here i am student in china and right now i am student of medicine here in china all the foreign students are ordered by their universities to leave the china as soon as the summer holidays starts with a reason that they cant provide security to foreign students in china well if china wanna organise olmypics and want the world to come and see their olympics why cant provide security to foreign students who are living in china for years if they cant provide security to foreign students how can they provide security to guests its a question ?