A bomb scare that led to the diversion of a US Airways flight to Philadelphia today was caused by a mistaken belief that a religious item was a bomb, Reuters quoted Philadelphia police as saying. A passenger was alarmed by the phylacteries, religious items which observant Jews strap around their arms and heads as part of morning prayers, on the flight from New York's La Guardia airport heading to Louisville. "Someone on the plane construed it as some kind of device," said officer Christine O'Brien, a spokeswoman for the Philadelphia police Department. There was no arrest and there were no charges, O'Brien said.