By Molly Daly

PHILADELPHIA (CBS) — Philadelphia police say charges have been filed against a Tempe, Arizona man, who is accused of telling security officers he had explosives while visiting the Liberty Bell on Independence Mall Saturday.

Forty-one-year-old Carlos Balsas is charged with making bomb threats and terroristic threats, reckless endangerment and related offenses after, police say, Balsas told security personnel, who were checking his backpacks, that his bags contained explosives. Balsas is a former professor at Arizona State University.

Balsas entered the Liberty Bell Center shortly after 10 a.m. and was stopped by security and told that he had to have his bags checked. It was at that point, Balsas said “I have explosives in there,” and then left the building, according to police.

National Park Service rangers caught up with Balsas and, after a brief struggle, handcuffed him about a block away on Market Street between 7th and 8th Streets. Market Street was shut down while police detectives and the bomb squad investigated.

No explosives were found.