Updated

A vicious assault on the son of an American U.N. diplomat in Geneva has caused alarm at the top tier of Swiss government.

The Foreign Ministry said Monday that President Micheline Calmy-Rey has written to Geneva authorities to voice concern at "the deterioration of the security situation in Geneva in recent months."

Geneva police spokesman Jean-Philippe Brandt says nobody has been arrested in connection with the nighttime attack in the center of Geneva last month.

Local media report that the assailants severely beat their victim before unsuccessfully attempting to throw him into the river Rhone.

The incident has added to concern among Geneva's large foreign and diplomatic community about a rise in muggings, break-ins and assaults in the self-styled "city of peace."