St. Louis police have reopened a small area of downtown after a suspicious package found outside an office building prompted a brief street closure.

The large cardboard box was discovered about 8 a.m. Thursday near a building in the 1500 block of Market Street. A robot was initially brought in to help deal with it. Bomb squad technicians then set off a controlled explosion 90 minutes later. Market Street was closed in the area and onlookers were kept away until police reopened the area shortly after 10 a.m.

Police Chief Sam Dotson later said the package was simply trash, though it had been "taped very precisely." He said the box contained discarded electronics.

The building houses many city offices, including municipal court. It is next to a large Post Office.

Joe Raedle, Getty Images