It went from quiet to a roaring wave of noise as helicopter after helicopter flew above the central Phoenix area on Thursday night. It left many confused and concerned.
ABC15 captured video of a black chopper hovering around the Sandra Day O'Connor U.S. Courthouse.
Crews aboard the chopper were also spotted exiting it, and landing on the roof of a federal building.
See raw video of special operation in video player above. (Courtesy: Josh deBerge)
From video footage and witnesses, the helicopters appear to be MH60 and MH6's, which are outfitted for special operations.
— Eric English (@EricEnglish15) November 20, 2015
Roads were shut down all around Jefferson and Washington streets. People nearby stopped and looked up, watching the scene unfold.
Some of the helicopters had blinking lights, while others were completely dark.
The Phoenix Police Department told ABC15 that this was a planned military training exercise, which have been going on around the Valley this week.
— Kim Tobin (@KimABC15) November 20, 2015
Authorities say these operations happen all over the country.
They said this really has nothing to do with the terror attacks in Paris.
"These military practices are planned months in advance for safety reasons," Sergeant Jonathon Howard, with Phoenix police, said. "There's a reason it was done here at 9 o'clock at night and we had the roads shut down."