The New York Police Department says the loud noise of a motorcycle backfiring caused a panic and sent people scrambling in Times Square.

The department tweeted Tuesday evening, "There is no #ActiveShooter in #TimesSquare. Motorcycles backfiring while passing through sounded like gun shots." The tweet also says the department received multiple 911 calls and urged the public to not panic saying "The Times Square area is very safe!"

Some people on Twitter thought the noise was an explosion, and that many people ran into buildings and stores.