WASHINGTON—As part of its routine series of preparedness drills aimed at testing national security, the Department of Homeland Security announced Monday that it had set free the five most deadly foreign terrorists in U.S. custody.

"Protecting the American people is our highest priority, so it is crucial that we periodically put our country's safeguards to the test," DHS Secretary Janet Napolitano said during a press conference. "Only by loosing these dangerous extremists on our infrastructure, landmarks, and chemical or nuclear facilities can we properly assess our vulnerability to terrorist attacks."

"If the Empire State Building or Jefferson Memorial blows up, for example, then we'll know we have to make some improvements," she added. "It's all part of the process."

The terrorists were reportedly transported separately by helicopter to undisclosed locations across the country and supplied with clothing, $10,000 cash, and a list of contacts known for making statements about crushing the U.S. government. The DHS also confirmed that the terrorists, who vowed nothing would stop them from their ultimate goal of destroying all of America, received a $100 Home Depot gift card for incidentals and supplies.

"To ensure the reliability of this exercise, not a single DHS employee or any federal or local law enforcement officers know where the terrorists are," Napolitano said. "We will give them a 48-hour head start before distributing their pictures and launching a nationwide search."

"In the meantime, we will have no contact with them, and will allow these talented and barbaric war criminals to do what they do best," Napolitano added.

Homeland Security officials said the drill will provide vital information on exactly how easily a hypothetical group of terrorists could exploit vastly underprotected and insufficiently funded areas such as Yosemite National Park, the Hoover Dam, most of the North American power grid, or virtually any U.S. port.

The department's deputy secretary, Jane Holl Lute, who personally analyzed background information on each of the incarcerated terrorists, said the "final five" were selected for the high level of risk they posed to the United States, their experience developing and executing terror plots, and their knowledge of explosives, as well as their overall remorselessness and leadership qualities.

The group comprises alleged 9/11 mastermind Khalid Sheikh Mohammed; senior al- Qaeda member Abu Faraj al-Libbi; 1993 World Trade Center bomber Ramzi Yousef; former al-Qaeda in Iraq commander Khaled al- Mashhadani; and 1998 U.S. embassy bomber Khalfan Khamis Mohamed.

"These terrorists are the absolute cream of the crop, I can assure you," Lute said. "No one else in American custody terrifies us more than these horrible, violent men."

Prior to their release, the terrorists were reportedly deprived of sleep, starved, and tortured in hopes of raising their anger levels and provoking them to coordinate a strike suitable for challenging the nation's readiness, response, and recovery efforts.

DHS spokesman Roger Munns said there was no reason for concern, since all the terrorists would most likely be apprehended during routine traffic stops well before they conspired to attack national defense utilities or used weapons of mass destruction to murder millions of innocent Americans.

"Some of them will certainly attempt to infiltrate some of our more vulnerable nuclear power plants in Texas or North Carolina, but the odds of them succeeding are pretty low, if you think about it," Munns said. "Although, off the record, I really hope they don't go after Chicago's mass transit system, because, let me tell you, that whole thing would go up in flames real quick."

NORAD Commander James A. Winnefeld, Jr. assured reporters that adequate security measures were in place to protect the American public and the plan would not fail as it did during the botched Sept. 11, 2001 security preparedness exercise.

"In our defense, we really didn't think it would be possible for them to hit both towers," Winnefeld said. "But with hindsight, I guess it's clear that we gave those guys way too much money and training."