Charleston, SC (WLTX) - It looks like the mystery of the planes over Lexington has been solved.

Last night, we got dozens of calls and e-mails and video about strange lights over Lexington and Calhoun Counties. In the videos, you could hear and see multiple planes apparently flying in formation at low-speed.

All the local military bases and airports said it wasn't them. Well, it turns out we now have what apparently is the answer.

A spokesperson for Joint Base Charleston told News19 Sunday morning that a group of 17 C-17 cargo jets with the 437th Airlift Wing took off from their base around 7 p.m. Saturday.

The large aircraft went cross-country to Nevada for a training exercise involving HALO drops--high altitude military parachuting. The exercise was done in coordination with multiple air military installations and groups, including the 82nd Airborne. As the group moved westward, more C-17s and other aircraft joined the effort.

It's part of a joint forceable entry exercise that's routinely done. The spokesperson said it would have been a large formation.

The event is a capstone event for students at the U.S. Air Force Weapons School located at Nellis Air Force Base in Nevada. The school uses this training mission to allow mobility air forces students to take what they have learned over the previous five months and apply it in a realistic training scenario simulating a high-end flight against a near-peer adversary.

More than 40 C-17s from 10 bases and more than 20 C-130s from three bases participated. It was the largest of one of these trainings in the weapons school's history.

The planes returned to Charleston around 6 a.m. Sunday.

All this matches up with other reports, including one that the same pattern of lights was seen near Denver, Colorado about 11 p.m. our time. There were also similar sightings in Missouri.