GENEVA, July 19 (JTA) — Swiss police are investigating whether a parcel left outside a Jewish building here was a bomb. The parcel, discovered last Friday night, contained electronic equipment that is normally used for a bomb, according to the Geneva police, who believe it was placed outside the headquarters of a local Jewish communal building in an attempt to spread fear among Swiss Jews. The mysterious package has been handed over to the Zurich police. Swiss Jewish leaders were reluctant to comment until police complete their investigation, but Thomas Lyssy, vice president of the Federation of Jewish Communities in Switzerland, said the incident was “without question a new escalation” in a recent wave of anti-Semitism in Switzerland. Jewish communities in Bern and Geneva, and the Israeli Embassy in Bern, have received hundreds of anti-Semitic letters since the head of a right-wing party here called for an immediate boycott of Jewish and American goods. The first Swiss business to heed that call took action last Friday. The Swiss supermarket chain Denner began a boycott of American goods in its 286 branches across Switzerland, a spokesman for the chain said. The boycott followed a call by the leader of the Swiss Democratic Party earlier this month that came after U.S. public finance officials decided to lift a moratorium on sanctions against Switzerland’s leading commercial banks. The American officials hope sanctions will pressure the banks to reach a settlement with Jewish groups on Holocaust-era claims. The Swiss Parliament is expected to discuss soon whether to lift the parliamentary immunity of Rudolf Keller, the president of the Swiss Democrats, who may be prosecuted for his call.