OAKHURST -- A 56-year-old man may face hate crime charges after he repeatedly assaulted another man on a charter bus from Modesto headed for Chukchansi casino Monday morning, the California Highway Patrol said. The man was set to be taken to the Madera County jail, CHP Sgt. Edward Greene said. The assault took place on a bus that left Modesto this morning en route to the casino. Greene said the assailant is a transient who got on the bus in Merced. The attacks occurred after passengers began collecting a tip for the driver, Greene said. The assailant apparently became angry when he saw that a 76-year-old man who speaks only Spanish did not contribute money for the tip and shoved him. He returned to his seat but got up and assaulted the older man four times, striking him with a closed fist, Greene said. The suspect used racial slurs during the attacks, Greene said. CHP units began to follow the bus, pulled it over on Lucky Lane near the casino and took the assailant into custody. The man did not have a gun but did have a knife, Greene said. In addition to the assault charges, the man may face additional charges because his victim was elderly and because he used racial epithets during the attacks, Greene said.