Sensitive documents from the Department of Homeland Security (DHS) that outlined preparations on how to deal with potential terrorist attacks at the Super Bowl were left on an airplane, according to a new report.

The documents were supposedly found by a CNN employee in the seat-back pocket of a commercial plane prior to Sunday's game between the Philadelphia Eagles and the New England Patriots. CNN reports:

The reports were based on exercises designed to evaluate the ability of public health, law enforcement and emergency management officials to engage in a coordinated response were a biological attack to be carried out in Minneapolis on Super Bowl Sunday.

The exercises identified several areas for improvement, including the problem that "some local law enforcement and emergency management agencies possess only a cursory knowledge of the BioWatch program and its mission."

The documents were marked "For Official Use Only" and included an "important for national security" warning. The reports were supposed to be kept locked up "at a minimum" and were to be shredded when discarded. CNN decided to withhold its report until after the Super Bowl after government officials warned that publishing the report could jeopardize security at the game.

"Who knows who else could have picked this up," Juliette Kayyem, a former DHS official who now serves as a CNN contributor, said. "The biggest consequence of this mistake may have less to do with terrorists knowing our vulnerabilities and more to do with confidence in the Department of Homeland Security. In the end, confidence in the federal government at a time of crisis is what the American public deserves."

The reports were found with travel itinerary and documents belonging to a senior government scientist in charge of BioWatch, a DHS program that deals with biological threats to national security.