A teenage Afghan migrant armed with an axe and a knife attacked passengers on a train in southern Germany, injuring four people before he was shot and killed by police as he fled.
Wuerzburg police said on their Facebook page that three of the victims suffered serious injuries and one was slightly injured. Another 14 people were being treated for shock.
German officials did not identify the victims, but Hong Kong's immigration department said that among those injured in the attack were four members of a family of five from the territory.
The department said it is working to provide assistance to the family but did give not give details of their injuries.
Bavaria's most senior security official, state interior minister Joachim Herrmann, told Germany's ARD television that the attacker had been identified as a 17-year-old Afghan.
Germany last year registered over a million migrants entering the country, including more than 150,000 Afghans, but it was not immediately clear whether the suspect was among them or was someone who had been in the country for a longer time.
Herrmann said initial information was that the suspect came to Germany as an unaccompanied minor and had lived in the Wuerzburg area for some time, initially at a refugee facility in the town of Ochsenfurt and more recently with a foster family.
He said authorities were still investigating the motive of the attack and were looking into reports that the suspect had yelled out "an exclamation" during the rampage.
Herrmann was responding to reports that some witnesses had heard the suspect shout "Allahu Akbar" ("God Is Great") during the attack.
The regional train was on its way from the Bavarian town of Treuchtlingen to Wuerzburg, which is about 60 miles north-west of Nuremberg.