GENEVA (JTA) — Nathan Kahn, a religious Jew from Zurich, was killed on the eve of Rosh Hashanah on his way home from synagogue.

The 55-year-old businessman was stabbed with a knife by a 46-year-old unemployed Muslim Turk who has lived in Switzerland since the 1970s. Kahn died of his wounds enroute to the hospital.

The motive for the crime remains uncertain, according to sources familiar with the case. It may have been a simple robbery even though the victim carried no money, sources said.

But a link to an extreme Islamic organization has not been excluded. Swiss police are investigating whether the assassin was acting on orders from abroad.

The suspect is also being investigated for the alleged murder of others.

Kahn, a father of four, was born in Haifa and immigrated to Switzerland in 1960. He worked collecting advertisements for the Jewish weekly Israelitishe Wochenblat, which is published in Zurich.