By Keith Laing - 08/16/12 05:04 PM EDT
TSA also said in its midyear report that its Pre-Check known traveler program had been expanded to five airlines and 20 airports. The program, which is part of the agency's move to "risk-based" security techniques, allows passengers to volunteer information in exchange for the possibility of receiving expedited screening.
The agency said it found 821 guns in passengers' carry-on luggage so far in 2012, of which 210 were loaded with ammunition.
"Firearms have been found at a total of 160 airports with Atlanta (ATL) TSO’s finding the most firearms – 56 found so far this year," Burns wrote.
TSA said it has also discovered a grenade, a bottle filed with flash powder and fireworks in passengers' luggage this year.