MCAS Miramar said Saturday the loud boom heard across San Diego County Tuesday evening may have been caused by aircraft training off the coast.
It occurred about 8:15 p.m. and residents — including San Diego Mayor Todd Gloria — took to social media to report hearing the boom.
"Yes, I heard it," Gloria wrote on Twitter. "No, I don't know what it was. I'll share if I get any information."
RELATED: Mystery Boom Heard Across San Diego County
At the time the boom was heard, two aircraft from MCAS Miramar were training about 30 miles southwest of San Diego over the Pacific Ocean, the Marine Corps Air Station said Saturday morning.
"While MCAS Miramar cannot account for every sound event that occurs within the area, in this case the cause is possibly due to aircraft training." military officials said.
"There are many different factors that would cause a sonic boom to travel large distances from its source," officials said. "Variations in temperature and humidity can create atmospheric conditions that can cause sound waves to travel farther than at other times."
The boom was heard as far south as Tijuana and as far east as El Cajon.
There were no reports of an earthquake occurring in the region at that time, according to the U.S. Geological Survey.
Camp Pendleton posted on its Facebook page June 3 that artillery units were scheduled to conduct live-fire training from Saturday through Friday and explosive munitions fire was expected between 6 a.m. and midnight each day.
