The incident happened just after 11 p.m. at 46th Street and 6th Avenue. Officers called in the bomb squad to investigate.
Meanwhile, officers closed off 6th Avenue between 45th and 47th streets, and 46th Street between Fifth and Seventh avenues.
People in restaurants and businesses in the area were told to move away:
Evacuated from @ChickfilA in Rockefeller centre. #Manhattan pic.twitter.com/M9RTEyYDE8
— Liam Healy (@HulkySmashSmash) July 21, 2016
After investigating, police gave the "all clear" signal just before 1 a.m. Thursday and the area was reopened.
The NYPD released this photo of the object:

Eyewitness News has a crew at the scene. Keep checking abc7NY for the latest on this developing story.