Buildings shook and windows rattled with a series of loud booms heard up and down the northern beaches of the Outer Banks of North Carolina, US, shortly before 11 a.m. Tuesday.
They may have been caused by aircraft breaking the sound barrier.
"The only thing we can attribute it to is offshore jets. We called the Air Force, the Navy and the Coast Guard and they couldn't run it down" - Sandy Sanderson, director of Dare County Emergency Management.
A military operating area - commonly called an MOA - is located about 25 miles offshore. The Dare County Range is a joint United States Navy/United States Air Force (USN/USAF) weapons range.