Air Force and Coast Guard aircraft will fly "intercept and identification" exercises over Washington tonight as part of efforts to prevent suicide aircraft attacks or other threats to the capital, a military spokesman said.

The latest exercise of what the North American Aerospace Defense Command calls "Falcon Virgo" involves Civil Air Patrol Cessna-182 light aircraft and a Coast Guard HH-65 Dolphin helicopter between 11:30 p.m. Monday and 5:30 a.m. Tuesday, NORAD said in a statement.

"We want to make sure people seeing these planes aren’t concerned," said NORAD spokesman John Cornelio.

"One of the reasons we put out notice of the exercise is so that anyone seeing a military aircraft in close proximity to a civilian aircraft will know that this is a controlled and carefully planned NORAD live exercise," he said.

No unmanned aerial vehicles will be used, said another spokeswoman.

Details of the scenario for the exercise could not be learned. However, it is expected to involve the helicopter intercepting the Cessna posing as a threat aircraft.

Airspace over the nation’s capital is tightly controlled and aircraft that stray into restricted airspace near the White House, Capitol, and national monuments risk being shot down by military aircraft.

During the September 11 terrorist attacks against the Pentagon and attempted strike on either the White House or Congress using hijacked airliners, U.S. military jets had to be scrambled from southern Virginia.

Since those attacks, the U.S. military has set up a defense system to better protect the region from such threats.

Past Falcon Virgo exercises have used F-16 jets based at Andrews Air Force Base, ground-based Avenger anti-aircraft missile batteries deployed at the southern end of the Navy-Air Force Joint Base Anacostia-Bolling, and Stinger and shoulder-fired Stinger anti-aircraft missiles deployed at undisclosed locations.

Cornelio said the main purpose of the exercise is to test the command and control system called the Joint Air Defense Operation Center, located at Anacostia-Bolling.

"The exercise is comprised of a series of training flights held in coordination with the Federal Aviation Administration, the NCR Coordination Center, the Joint Air Defense Operations Center (JADOC), Civil Air Patrol, U.S. Coast Guard and CONR's Eastern Air Defense Sector," the NORAD statement said.

"Exercise Falcon Virgo is designed to hone NORAD's intercept and identification operations as well as operationally test the NCR Visual Warning System and certify newly assigned command and control personnel at JADOC."

The exercises are part of the military’s "rapid response capability" for the region, the statement added.