A mechanical failure led to the accidental release of six training bombs and a training missile over the skies of Michigan last month. officials believe.

WPBN reported that no one was injured when the training munitions, which were not explosive, fell on Oct. 25 from an A-10 Thunderbolt Michigan Air National Guard aircraft. The bombs emit smoke to make their landing spots more visible during training.

The plane was one of a group traveling from Selfridge Air National Guard base outside Detroit to Camp Grayling, about 200 miles northwest of the city.

Officials realized that a rack of training weapons had fallen from one of the jets over Oscoda County, WWTV reported.

"The phase of the flight they were in was prior to arriving to the range, so the operating procedure for that would be to have all weapon systems saved up, so there wouldn't even be any switches, as it were, that were hot at that point," Lt. Col. Matthew Trumble, director of the Camp Grayling Air Gunnery Range, told the news station. "That's why we suspect it was most likely mechanical fault."

The Michigan National Guard told WWTV that the bombs and the missile were recovered near Luzerne.

Trumble called the situation "pretty darn rare."

"In the 20 years I've been doing this, I haven't seen a case like that," he said.

The munitions fell into a remote wooded area away from homes and businesses, WPBN reported.

Authorities are investigating to determine what caused the drop.