What to Know An evacuation of the Trump Tower lobby late Tuesday afternoon sparked a brief scare as visitors were suddenly ordered out

The NYPD says concern over an attended bag at the Niketown store prompted investigation, including by the bomb squad

The package turned out to be a backpack of children's toys, and an all-clear was issued

The lobby of Trump Tower was briefly evacuated late Tuesday afternoon as police investigated a suspicious package that turned out a be an unattended backpack filled with children's toys, the NYPD tells NBC 4 New York.

Visitors in the lobby of the building at 56th Street and Fifth Avenue were seen being ushered out quickly, NBC cameras show. Many began sprinting out as armored police yelled, "You gotta get out, let's go, let's go."

A senior NYPD official tells NBC News that a suspicious knapsack located near the Niketown store in the building led officials to clear the area in the Trump Tower atrium, which is open to the public.

A bomb squad was called as a precaution to investigate, and the bag was deemed safe shortly afterward, the NYPD said. It contained children's toys.

The investigation exacerbated gridlock around the midtown block, which has already been partially closed off since Trump was elected president. Holiday traffic and rush-hour traffic had also congested the area.

President-elect Donald Trump lives in the tower and has his offices there, though he was at his Mar-a-Lago estate in Florida when the bag was discovered.

His newly appointed press secretary, Sean Spicer, tweeted that officials were "back to work" following the "false alarm."

He added, "Thanks, NYPD."

That prompted Mayor Bill de Blasio's press secretary Eric Phillips to fire back on Twitter: "No problem, we'll send you the bill."

The Twitter tiff reignites de Blasio's request that the federal government reimburse the city's $35 million to keep the president-elect safe through the inauguration. Congress has only offered New York City $7 million.

It is not clear how much it would cost to protect the president-elect and his family once he moves into the White House after the Jan. 20 inauguration. Trump's wife, Melania Trump, and their son Barron plan to remain in Manhattan until at least the end of the school year. But Trump says he will make frequent trips back to NYC to see his family.

The security includes an NYPD detail at Trump Tower, the Fifth Avenue skyscraper where the president-elect lives and works.

The amount sought by New York City covers security costs between Nov. 8 and Jan. 20.

Trump Tower, in addition to being the president-elect's home and business headquarters, contains residences, restaurants, retail stores - and a lobby that by law is open to the public to visitors daily from 8 a.m. to 10 p.m.

Police receive about 42 reports every day of so-called suspicious packages, though that number can surge depending on current events. In the days after a pressure cooker bomb exploded earlier this year in New York City, police responded to more than 800 calls of "suspicious packages."

Maria Beckford, visiting New York from her native London, was in Niketown with her 13-year-old son looking to buy a pair of soccer cleats when she said they were told to urgently leave the store.

"We actually had them in his hands but because of everything we just had to leave," she said.

Law enforcement and military have recently been training on how to safely bring Trump out of New York City in case of an emergency: U.S. military planes spotted flying over midtown a few weeks ago turned out to be part of an emergency relocation drill to figure out where military choppers could touch down near Trump Tower and move the president-elect and others out toward safety.