What to do if a foreign student is getting racially bullied and isn‘t aware?

There is this new student who has been attending my university last year. He came from Zimbabwe and can’t speak/ fully understand English properly. Ever since his been attending the university, his been getting verbally abused racially by a group of white females and most of the time he cannot fully understand what they are saying. One day he opened his bag in class and these bunch of banana skins fell out and everyone in class started laughing but him. I don’t think he is aware of what is going on sometimes or what they are saying. They’ll leave pictures of monkeys in his bag and make monkey noises when he comes in but I don’t know if he can pick up on this. He is kind of a loner and most people don’t like him, its like they want to join in and insult him too. Sometimes these females will go up to him and verbally insult by shouting words to his face but most of the time he just tries to ignore them or walk away. They say things like he smells even though he doesn’t, his ugly. But I can tell that he doesn’t know some of what they’re saying as they speak in slang. They use the fact that he knows little English to try to get him in trouble. Recently they somehow stole this guy’s phone and they put it in his bag without him knowing. Now when they came to search him and found out he had it, he almost got beaten up by these group of boys and he seemed confused. I feel so sorry for him because he doesn’t even seem aware of what’s going on because of his little understanding of English. He always looks depressed and confused.