A man threatening to blow up the Liberty Bell was detained Saturday, police said, after leaving two backpacks nearby that he said contained explosives.

Police investigated and found no explosives.

The man was expected to be charged, Officer Christine O'Brien, a spokeswoman for the Philadelphia Police Department, said Saturday evening. He had not been identified as of late Saturday night.

A police source said the man was not from the Philadelphia area and did not appear to have a criminal record.

Sometime before 10:45 a.m., National Park Service rangers stopped the man Saturday morning, after reports that he was threatening to blow up the Liberty Bell. The man also said he had explosives in his backpacks, O'Brien said.

Two black backpacks were found in front of the Liberty Wheels wheelchair and scooter rental shop at 714 Market Street, a half-block away.

Police arrived around 10:45 a.m. and closed off Market Street between 7th and 8th Streets.

Shortly after, a member of the Philadelphia Police Department's bomb squad unit began examining the backpacks. Other members of the unit arrived later, going back and forth between the bags and the testing equipment in their van. The results came back negative for hazards, a bomb squad officer said.

Market Street reopened to pedestrians and traffic around 11:45 a.m. The Liberty Bell remained open throughout.

Agents with the Bureau of Alcohol, Tobacco, Firearms, and Explosives responded alongside Philadelphia police to assist the National Park Service at the scene.

The joint investigation is being carried out by the Philadelphia Police and FBI, confirmed Special Agent Frank Burton Jr., spokesman for the FBI's Philadelphia division, because the Liberty Bell is a federal landmark.