Something rattled houses in the Keene area Wednesday, and despite official reports to the contrary, many residents are convinced it was a sonic boom.

Residents reported a loud noise about 2:15 p.m., with many saying it shook their homes and rattled windows.

"It was a loud boom," said Swanzey resident Jim Vitous. "It shook the whole house."

Vitous had just put his twins down for a nap, but they didn't stay asleep for long. A rushing noise lasting two or three seconds got their attention, Vitous said.

"I thought a propane tank blew up or something hit the house, a truck hit the house or something," he said. "But then after that, we figured something that loud that was heard all over was a sonic boom."

But the Massachusetts Air National Guard said that wasn't not the case. Officials said jets from the Massachusetts Air National Guard were in the area training, but they said they didn't break supersonic speeds.

"Air traffic control officials confirmed via their tracking systems that the sound barrier was not broken by our jets," the National Guard said in a written statement. "Additionally, the pilots reviewed their on-board recording systems to verify that their speeds were subsonic."

The Massachusetts National Guard said the noise was simply the sounds of jet engines.

Comment: So it wasn't a sonic boom, but it was the sound of jet engines. Right...

The New Hampshire National Guard said that Massachusetts pilots have flown supersonic before, including in February 2013 when a pilot training with the 104th Air Wing broke the sound barrier, causing a sonic boom.

FAA regulations say it's illegal to do that over highly populated areas, such as Keene.

"Everyone was a little startled and on alert wondering what it was," said Wade Newer of Keene State College.

Newer said it seems that almost everyone at the college felt it.

"I grew up in southern California in the '60s and heard sonic booms before, and it definitely could have been something like that," Newer said.

Whatever it was, it seems to involve the National Guard's training.

"It was disturbing," Vitous said. "Something like that, we should be alerted to. We have kids at school and kids at home, and it really put us on notice."

The New Hampshire National Guard said that as a courtesy, Massachusetts usually notifies it if it's doing any maneuvers in New Hampshire, but that didn't happen Wednesday. The New Hampshire Guard said that if Massachusetts had, it would have been able to contact local authorities and let them know what was going on.