A 50-year-old Orthodox Jew suffered serious injury when he was stabbed while walking along a street in Zurich, Swiss police reported on Sunday. Police arrested a 15-year-old male suspect following the attack, which took place in the northern Swiss city on Saturday evening. The ongoing investigation by Zurich Canton police and state prosecutors for juvenile offences included the possibility of a racist motive, the police statement said. Police appealed for witnesses to come forward.