Sonya Ataou, whose 21-year-old son was among the witnesses who helped remove the pair from the bus, told WalesOnline: "People told the man to be quiet and he started shouting at people on the bus. He went up to the boy and said ‘where are you from?’.
“He then started verbal, antisemitic abuse. Everyone on the bus was standing up for the boy.
“The driver stopped the bus and told them to get off. The guy left the bus but the woman went for the boy. She hit him in the head and he was bleeding."
South Wales Police, which clarified the victim was 38 after reports he was "young boy", said: "Officers have made arrangements to speak to the victim and witnesses to obtain further information."