PORTLAND, Ore. (KOIN) — From the Oregon coast to parts of central Oregon, homeowners reported hearing what sounded like explosions Monday night. Others thought their house shook.

No damage was reported, but KOIN 6 News found out there were at least 3 possible reasons for the strange noise and shaking.

The Oregon Air National Guard’s 142nd Fighter Wing is doing nighttime training missions this week. The fighter jets leave Portland Air National Guard base and head to the Oregon coast.

They’re training to protect the skies from northern California to the Canadian border. The F-15 Eagle fighter jets are on 24-hour alert, and the nighttime flying maneuvers and practice are Air Force requirements.

And the F-15 fighter jets in the 173rd Fighter Wing, based in Klamath Falls, was also doing nighttime practice. Pilots in training practice mock aerial battles along the coast.

National Guard staff told KOIN 6 News the heavy cloud cover is another reason the jet noise was amplified.

Meanwhile, near Lebanon and outside Corvallis, a 1.6 earthquake rolled through. No damage was reported, and neither the Corvallis police or fire departments reported getting any calls.