A large explosion was heard near Harrogate just before 4pm on 26 Jan 2012. It was heard on the outskirts of Harrogate, Menwith Hill and Sumemrbridge.
It is thought that it was the result of a sonic boom caused by a low-flying aircraft.
Geological experts confirmed that there was no earthquake recorded in the area and the Met Office confirmed that there were no major weather problems that could have caused the bang.
Officers have not found any evidence of an explosion or any other incident that may have caused the loud noise some people heard.
There were Royal Air Force and Royal Navy aircraft in operation over the skies of Yorkshire today part of a major training exercise to prepare for this year’s Olympic Games.