Clintonville, Wis. residents endured another night of mysterious booms and bangs that appear to be getting worse since starting on Sunday.

Residents of Clintonville, which is located approximately 40 miles west of Green Bay, have been complaining about unexplained booming noises. Police say just before 3 a.m. on Tuesday, residents in the area experienced the latest in unexplained booms. There are indications from witnesses that the booming is spreading to areas south and west of the original locations, reported WTAQ.

Sunday night, Clintonville police started receiving reports regarding explosions or explosion like sounds. They reportedly were receiving 50 to 60 calls at one time.

Residents don't know what to make of it.

[It] almost felt like a heavy-duty thunderstorm, said Al Miller, according to Fox, as another resident had said that it sounded like a bomb had gone off.

Clintonville City Administrator Lisa Kuss reportedly met with civil engineers and geologists on Tuesday morning. Officials are checking the water system to see if there are any problems. Officials are also checking gas lines, sewers and water pressure systems, but they have yet to find a source of the loud noises.

Kuss believes the noises are coming from underground, reported the AP, and the next plan is to check well pumps to make sure they are operating properly.

Some scientist agree with her.

Cliff Thurber is a geophysics professor. According to Fox, he reportedly believes that the odd booms not look like what normally happens when you have earthquakes occurring.

The ground is shaking in an unusual way, said Thurber.

City leaders said there were no mining explosions or explosive companies in the area. The military said they were not conducting any type of weapons testing or any operation that would cause a booming sound, reported WGBA-TV.

City officials said they believe the public is safe, but if there are asking residents to contact Clintonville police department at its non-emergency number if they hear any more loud booms.