The 31-year-old German citizen boarded the train at a station in Saxony near the border to the Czech Republic. At a subsequent stop the 15 year old entered the train with two Syrian companions.
According to accounts given by the teenagers, the man started to insult them in the train and gave them the Hitler salute. He then punched the young Afghan in the face.
The teenagers got out of the train at a stop near Plauen, but the man followed them and started to physically assault the young Afghan. When his victim had fallen to the ground, he repeatedly kicked his head against the ground, the refugees recounted.
The teenager was brought to hospital in an ambulance. The police were unable to give further details on the extent of the injuries. The man, who was recorded with 1.9 per mille of alcohol in his blood, is now being investigated for serious assault and a crime with a racist motive.
Crime statistics released by the Interior Ministry revealed that a record 39,000 politically motivated crimes were committed in 2015, a surge of almost 19 percent on the previous year. A majority (23,000) of those crimes had a far-right motive behind them.