SAN DIEGO (KGTV) -- San Diego County residents are scratching their heads after a mysterious boom shook the ground Tuesday afternoon.
Several area residents reported observing what they say felt like an earthquake around 5 p.m.
"It was weird the ground didn’t move like an earthquake but my windows did," one resident said on Facebook.
The United States Geological Survey didn't report any activity in the area Tuesday.
“There was no earthquake recorded in San Diego today, but it may have been a sonic boom which are not too uncommon there,” the agency reported.
10News also reached out to Chula Vista Police, which said it hadn’t received any calls regarding the strange shaking.
Residents from all over the county reported either a roll or shake, or hearing a rumbling sound.
"I heard a rumbling before the shaking started. I wonder what it was?," commented Andrea Bingham.
"I was in Mission Valley in a store when I saw the shelves shaking, I didn’t know what it was," wrote Ana Chambers.
"I heard a boom but no rumbling of the ground in Paradise Hills," said Veronica Couoh.
Camp Pendleton officials said the base regularly shoots high explosive munitions, but that it’s unlikely what caused the shaking in the region.