For several days in this week, people in Boston and the surrounding area have heard large helicopters flying around the area.

Many people reached out to media with concerns that the helicopters were passing very close to buildings.

FOX25 found a video posted on YouTube showing that several helicopters flying low above the high rise buildings in Boston.

Boston police has sent out a community advisory to alert residents about a planned training exercise in conjunction with the defense department. The advisory said that the training was not in response to any world events.

FOX25 reached out to the Boston Police Department and told “specifics are kept mysterious for good reason.”

The Blackhawk helicopters were lined up on the tarmac at a local airfield on Wednesday. The Department of Defense would not comment on the exercise.

The exercise had been expected to continue until Friday, and FOX25 has told the Boston Police Department to release more information after it ends.

By Prakriti Neogi