WASHINGTON — A US national pleaded guilty Tuesday to obstructing the vision of military pilots during training, AFP learned from a legal source.

Robert Bruce, 56, faces up to 20 years in prison for repeatedly pointing a laser beam at US Navy pilots flying over and around Naval Air Station Oceana, in the eastern state of Virginia, according to court documents cited in a statement from the prosecution.

Numerous calls to the station's "Community Noise Complaint Line" included a threat that if he had a rifle, "he would take potshots at the aircraft," according to the statement.

"Laser harassment of aircraft not only places pilots and passengers at risk, but also endangers those on the ground," said Virginia prosecutor Neil MacBride.

"Those who choose to place our military personnel in peril should be on notice that their conduct is against the law and will not be tolerated."

The F-18 pilots, "endangered multiple times by laser dazzling during landing practice," eventually found Bruce when they "pinpointed the origin of the laser with a mapping device, leading authorities to Bruce's home."

Agents of the Naval Criminal Investigative Service obtained video recordings of Bruce in the act, before his arrest on June 5.

Bruce will be sentenced on October 19.