The downtown Philadelphia building that houses the Liberty Bell and the streets around it have been evacuated because of a suspicious item that looks like a balloon.
National Park Service rangers called police on Thursday afternoon. Park Service spokeswoman Jane Cowley says it's unclear whether the item is inside or outside the Liberty Bell Center.
A police department spokeswoman says the suspicious item is described as a blue balloon-shape container with a white powdery substance on it.
Police and fire officials are at the scene. The Liberty Bell Center and the streets near it have been closed as they investigate.
No injuries have been reported.