Australian Police are investigating mobile phone footage showing a woman's racist tirade on a Sydney train.
It shows a passenger standing up to her abuse before the woman assaults him.
Witnesses say the woman was targeting foreign commuters.
"She was being really racist towards Asian people, because she was saying 'go back to your own country'," said witness Candy Li.
Police arrested a 52-year-old woman at Strathfield station on Saturday. She was reportedly taken to hospital where she was treated under the Mental Health Act.