News 12 received calls Tuesday evening from multiple people claiming to have heard loud explosions on the South Shore.
The calls came from residents in Lindenhurst, Copiague, Babylon and West Islip areas. Some said their houses shook.
Suffolk County police said they received nearly two dozen calls regarding the sound, but nothing was found.
The Defense Department told News 12 it is looking into the reports.
In January, residents also reported hearing loud booms. It turned out that the U.S. military was conducting offshore training exercises with supersonic fighter jets.