The visitor center at Independence Hall in Philadelphia was briefly closed Sunday in a bomb scare amid tension after the Boston Marathon bombings.

The police bomb squad gave the all-clear after a few tense moments at the Independence Visitor Center and adjoining garage, the Philadelphia Inquirer reported.

Concerns about the possible existence of a bomb had closed the site shortly after noon. It reopened just before 1:30 p.m.

Lt. Joseph McGarrey said the center was evacuated after a "suspicious person" dressed in camouflage fatigues and driving a vehicle loaded with many "items" -- including paper and clothing -- was detained for questioning.

He said the center at 6th and Market Streets was searched by police dogs and the bomb squad, and no explosives were found. It is across Market Street from the Liberty Bell.

The investigation was a joint effort by the National Park Service, Philadelphia police and transit police.