US Air Force fighter jets intercepted a civilian aircraft flying in the temporarily restricted airspace near Donald Trump’s Florida home, bringing the number of violations to more than 20 since the president took office on January 20.

North American Aerospace Defence Command (NORAD) said that Sunday’s incident, which took place as Trump finished a round of golf at his West Palm Beach golf course, saw F-16s deploy flares to get the attention of the civilian pilot.

Jets also conducted an intercept on Saturday morning shortly after Trump arrived at the course from his private Mar-a-Lago club and residence.

The airspace intrusions in the heavily congested south Florida airspace have prompted fighter jet intercepts but did not alter Trump’s schedule or impact his security, officials said.

NORAD says the flares may have been visible from the ground but that they burn out quickly and don’t pose danger.

Federal officials maintain a permanent flight restriction over Trump’s club that expands to a radius of 30 nautical miles (55km) when the president is in residence.

Violations, and intercepts, are relatively routine, but NORAD is raising alarm over the frequency of the intrusions since Trump’s inauguration, saying it has responded to more than 20 incidents and blames civilian pilots for not following regulations requiring them to check for airspace restrictions before taking off.

“Adherence to TFR (Temporary Flight Restriction) procedures is essential to ensure flight safety, national security, and the security of the President,” General Gregory Guillot, the commander of NORAD and US Northern Command said in a statement.

“The procedures are not optional, and the excessive number of recent TFR violations indicates many civil aviators are not reading Notice to Airmen, or NOTAMS, before each flight as required by the FAA, and has resulted in multiple responses by NORAD fighter aircraft to guide offending aircraft out of the TFR.”