*UPDATE 8/24 5:15 p.m. – The earthquake's intensity has been increased from 2.0 to 2.2.

*UPDATE 8/24 3:10 p.m. – The U.S. Geological Survey on Thursday afternoon confirmed a 2.0 earthquake less than 4 miles southeast of South Portland offshore of Cape Elizabeth.

207: Maine author's new book says we should be concerned but not afraid of earthquakes

CAPE ELIZABETH, Maine (NEWS CENTER) — A loud, mysterious boom shook the Cape Elizabeth region around lunchtime Thursday.

A NEWS CENTER viewer said it shook his house, and friends have commented on social media wondering what caused the sound.

Cape Elizabeth police said they got at least a dozen calls about it. Officers heard and felt it, too.

NEWS CENTER asked police if it could be a sonic boom from the Blue Angels flying team, which is in Brunswick for the weekend. The officer said that idea was dismissed in their department.

There isn’t any report of a propane explosion in the community, either.

NEWS CENTER Chief Meteorologist Todd Gutner tweeted “Anyone feel that?”

He got more than a dozen responses, including a tweet from Peter Nichols who said he felt the ground shake and heard the loud boom in South Portland, too.

Police as of Thursday afternoon said they didn't have a clue as to what may have caused it.