People are reporting they felt the ground shake Saturday morning in South Jersey.
The U.S. Geological Survey and the National Weather Service are not reporting an earthquake in the area. However, there is speculation it could be a sonic boom, according to the USGS.
Joint Base McGuire-Dix-Lakehurst spokesman Pascual Flores told NBC News on Saturday, "There currently is no training of any type that would have resulted in today's incident."
The New Jersey National Guard last weekend conducted artillery-fire training that it told the public about in advance.
New Jersey residents in Atlantic, Cape May, Ocean, Salem and Camden County are chattering about what they felt, what they heard and when it happened.