The two prior answers are good. I want to add that you should ask your coordinator/managing professor about this, because the scope of what's acceptable on your part will vary by culture and institution. 

Perhaps some professors will say, "Just tell them to leave." Other institutions may highly encourage or require proof of regular attendance for funding or legal purposes, and therefore culturally prohibit telling students not to come to class in any event. 

When my father was at any Ivy professional school in the 1960's, one professor could reputedly grab a distracted student without warning by the shirt collar, physically throw him out of the room, and lock the door on him. Surely that's not allowed anywhere anymore.