A 58-year-old woman alleges she was attacked and repeatedly punched by a Swiss man inside a supermarket in the southern province of Trang on Tuesday afternoon.

Natchanan Khikkham told reporters the incident began when the man, aged about 60, shoved her while they were inside the Big C store.

She said she responded by telling him to be polite, and asked why he did it.

According to her, the man then shouted at her, and she walked away.

Ms Natchanan said the man followed her and then punched her more than once and walked away. She responded by throwing a water bottle, but missed him.

She alleged the man walked back to her and then knocked her to the floor, pressed his knee against her neck and punched her repeatedly in the face. She called for help.

Ms Natchanan said store staff called paramedics to the scene. She was taken to Trang Hospital and treated for cuts to her face, a broken nose and swelling around her eyes.

Police took the man to Trang police station, where he refused to answer any questions.

It was reported the man is in Thailand on a retirement visa.