New Jersey State Police said on Friday they were investigating packages containing a "suspicious" substance sent to sites near the stadium where the Super Bowl will be played on Sunday, but no injuries were reported.
Local media said the packages were sent to sites including six hotels and the office of former New York Mayor Rudolph Giuliani in Manhattan. Reuters was unable to confirm all the locations, and Giuliani's office did not immediately respond to a call seeking comment.
At an Econo Lodge hotel in Carlstadt, New Jersey, which had received an envelope containing a loose white powder, hotel general manager Eylem Naik said that authorities had tested the powder and pronounced it harmless.
"Everything is under control," Naik said. "They are leaving the premises now."
New York and New Jersey police have been out in force throughout the metropolitan area ahead of the February 2 NFL championship game. Met Life Stadium in East Rutherford, New Jersey, about 10 miles west of New York City has been on lockdown since Sunday.
Both teams, the Denver Broncos and Seattle Seahawks, have been staying at hotels in Jersey City in the week leading up to the game.