A couple of loud booms heard over the region around noon Monday were likely caused by Growler jets from Naval Air Station Whidbey Island.

Two distinct sonic booms could be heard in rapid succession over Aberdeen. Grays Harbor Fire District 8 Commissioner Stephanie Allestad reported the sound was caused by the military. Tom Mills, a spokesman for the base, confirmed the sound was likely caused by Navy Growler jets performing a “functional check flight” off the coast.

Growler jets are Boeing products used as carrier-based electronic warfare aircraft. The jets make training flights over the Olympic National Park and across the Olympic Peninsula, the noise from which is the subject of lawsuits filed by a group of Whidbey Island residents and State Attorney General Bob Ferguson.

According to the Associated Press, there are 82 Growlers stationed at Whidbey Island, and more than 30 additional jets will be coming in March. Ferguson’s suit claims the Navy will increase Growler flight training to nearly 100,000 annual takeoffs and landings over the next 30 years.

Comments, including noise complaints, can be directed to the air station’s comment line at 360-257-6665 or by email at comments.naswi@navy.mil.