Trump Tower in New York City was evacuated on Tuesday (local time) after a suspicious package was found.
The bag, found near a Nike store, was later found to contain children's toys, a senior police official told NBC News.
Police had asked people to leave the building and clear the area around the 58-storey skyscraper.
Pictures and video on social media showed people running in panic from the tower, which is currently home to US President-Elect Donald Trump.
Mr Trump was not in the building at the time, according to reports.
The all-clear was given less than a half-hour after the evacuation. The bomb squad had been called in as a precaution.
The Fifth Ave tower in Midtown Manhattan has been under intense security following the November election, when the Republican billionaire won against Democrat Hillary Clinton.
Barricades have been in place for weeks around the tower, with the NYPD guarding the site.
Mr Trump will be sworn in as US President on January 20 in Washington DC.