Thundering black military helicopters swooping low in the skyline have been a troubling site to some residents this week, especially with another 9/11 anniversary around the corner. But the flights are part of routine training, the Star Tribune reports.
The helicopters, Black Hawks and smaller Hughes 500s, have been spotted since Aug. 19, when urban-environment training began in Minneapolis-St. Paul, according to the U.S. Special Operations Command, which is supported by local police. The Pioneer Press reported on it last week.
The flights became more visible to residents around the Twin Cities on Sunday. People may see the choppers between 7 p.m. and midnight through Saturday.
Here's a few glimpses of the helicopters: