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.