A man has been charged with allegedly following a woman off a TTC bus and sexually assaulting her in the west end of the city.Police were called to Eglinton Avenue and Dufferin Street around 12:30 a.m. Thursday for reports of a sexual assault.It’s alleged that the suspect and victim both exited a TTC bus, and the suspect followed the victim before approaching her from behind.The suspect then allegedly grabbed the victim and sexually assaulted her. She managed to break free and ran from the suspect, who continued to follow her until a passerby intervened.Samuel Opoku, 29, of no fixed address, has been charged with sexual assault, criminal harassment and breach of probation.Investigators say there may be other victims and encourage anyone to come forward and contact police.