Food Network denies link to powder-filled balloon that prompted evacuation at Liberty Bell

PHILADELPHIA (AP) — Police are investigating the source of a powder-filled balloon that forced the evacuation of the Liberty Bell Center in Philadelphia.

Spokesman Lt. Frank Vanore said Friday that city police questioned whether it was linked to the taping of a TV program.

But a Food Network statement says no balloons were used in the Thursday morning taping of "Chef vs. City."

A guard discovered the stray balloon outside the Liberty Bell entrance that afternoon, leading authorities to shut down the area. The FBI says tests show the powder was not hazardous; the National Park Service says it was flour.

Meanwhile, police say powder found on a letter sent to a municipal office building near City Hall that prompted a limited evacuation Friday was not hazardous.