Documents from the Department of Homeland Security detailing the response to exercises conducted in the event of a biological attack on Super Bowl Sunday were left on a commercial airplane and found by a CNN employee, according to the news outlet.

The documents, described as an “after action report” and marked “For Official Use Only,” were dated December 2017 and were related to two drills conducted to measure the coordinated response from public health, law enforcement, and emergency management officials if a biological attack were to occur in Minneapolis on Super Bowl Sunday.

According to CNN, a company employee found copies of the report in the seat-back pocket of an airplane. Along with the report, the employee also found the itinerary and boarding pass of the government scientist who serves as the program manager of BioWatch, which conducted the exercise.

BioWatch is a Department of Homeland Security program designed to assist communities with preparing a coordinated response to a bioterrorism attack and "provides early detection of" such attacks.

A spokesman with the Department of Homeland Security told CNN the drills didn’t stem from a specific threat.

“This exercise was a resounding success and was not conducted in response to any specific, credible threat of a bioterrorism attack,” Tyler Q. Houlton said.

Two exercises, one in July and another in November, were conducted to evaluate the response to a simulated anthrax attack on Super Bowl Sunday.

The after-action report found “some local law enforcement and emergency management agencies possess only a cursory knowledge of the BioWatch program and its mission.”

The report also noted there were “differences of opinion” regarding how many people were exposed, “which led to differences of opinion on courses of action.”

The document further found local health agencies were confused about the alerts issued during the drills, as well as who to safely share information with during an emergency.

This confusion “made it difficult for them to assess whether the city was at risk,” the after-action report stated, according to CNN.

A DHS official told CNN that the issues identified in the draft reports were addressed ahead of Super Bowl LII.

CNN could not verify who left the report on the plane.