Military helicopters flew over the Twin Cities overnight, and may continue to do so for several days, authorities said.

The 160th Special Operations Aviation Regiment, out of Fort Campbell, Kentucky, flew five to seven black helicopters through Minneapolis and St. Paul last night. Various models were flying low through both downtown St. Paul and Minneapolis and skimming in formation over neighborhoods between the downtowns at dusk and into the night last night.

A spokesman for a military special operations team apologized to Twin Cities residents for any inconvenience caused by the exercises.

Public Information Officer Major Allen Hill said local law enforcement typically alert the public an hour before the exercises begin, but the military doesn't want much advance publicity to avoid crowds.

The special ops training takes place 10 to 12 times a year in cities throughout the United States. They'll conduct nightly exercises in the Twin Cities through Thursday.

It's similar to an exercise in 2012. Those flights lasted for most of a week in late August that year.

St. Paul police called last night's flights a "training exercise," and Minneapolis police spokesman Scott Seroka said Minneapolis police were also involved in the activity.

"These are Department of Defense exercises that should not be shared with the general public and security is of the utmost concern," he said in a statement, issued after a flurry of reports about the helicopters on social media in the Twin Cities.

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