The bomb squad was X-raying the soft-sided cooler found on the pedestrian mall and planned to determine whether it posed a threat, Browne said.
No evacuations have been ordered from buildings, but workers were told to stay indoors as the police responded.
Police cordoned off the square with yellow tape, while yelling "Get back, get back" at onlookers and guiding bomb-sniffing dogs through the area.
Cars approaching the area were told to turn back as an eerie silence descended on the area.
The package was found at 46th Street and Broadway around 1:15 p.m. in front of the Marriott Marquis Hotel, but the hotel had not been evacuated.
Three blocks around Times Square were closed as a precaution because the cooler was found about a block from where a smoking SUV and failed car bomb was found Saturday night.
Henry Goldfine, an attorney from New Jersey attending a meeting at the Marriott Marquis, said he had planned to relax on the Times Square pedestrian mall but was turned away.
"Instead, I'm going back where there's no air and no light," Goldfine said, standing near the hotel. "We don't have things like this in New Jersey."
On an average day, police get 90 to 100 reports of a suspicious package. Since the failed car bomb attack Saturday on Times Square, that figure has risen about 30 percent.
One earlier Friday was reported near the area where the car bomb was discovered, but turned out to be someone's lunch.
