A series of routine training exercises over the next week may bring low flying military helicopters to the metro area, a Minneapolis police spokesman said. The UH-60 Black Hawk (top right) and Hughes 500 helicopters (below right) may be seen or heard as training continues over the next week between 7 p.m. and 12 midnight, according to Sgt. William Palmer of the Minneapolis Police Department.

"This announcement is being made to alert residents and prevent the overload of the 911 system with concerned callers," Palmer said in a statement released Friday afternoon.

The exact time and location of the training exercises will not be released, he added. Similar "urban-environment" exercises have been held this year in Chicago and Los Angeles, he said. The exercises do not involve local forces.