Officials are trying to determine the cause of some reported rumblings that shook parts of the Garden State from the southern Jersey Shore to the New York City metropolitan area.
The U.S. Geological Survey said Wednesday afternoon that nearly 100 people from Cape May to Jersey City and Hackettstown.
NBC10 in Philadelphia, meanwhile, reported that viewers heard and felt the boom well into Pennsylvania.
The USGS didn't reveal a cause and didn't post whether the boom, estimated to originate off the coast of Cape May, registered on the moment magnitude scale.
And National Weather Service said there was "nothing weather-related" that would cause the booms.
Previous sonic booms in the area have been caused by military aircraft during tests and training over the Atlantic Ocean.
No injuries or damage were reported.