() U.S. fighter jets were scrambled twice over the weekend to intercept civilian aircraft in the skies over Palm Beach, Fla., where President Trump was at his Mar-a-Lago estate.

The North American Aerospace Defense Command said the most recent incident occurred around 1 p.m. Florida time on Sunday when NORAD aircraft escorted a civilian aircraft out of the area after setting off flares to get the pilot’s attention.

The airspace over Trump’s property has a permanent flight restriction that expands to a radius of 30 nautical miles when the president is in residence.

NORAD said its aircraft have responded to more than 20 “tracks of interest” since Trump took office on Jan. 20. The agency reported three interceptions just last week.

The military command reminded pilots to stay current on the “Notice to Airmen,” or NOTAMs, issued by the federal government, which include Temporary Flight Restrictions, or TFRs.

“The excessive number of recent TFR violations indicates many civilian aviators are not reading” the notices, Air Force Gen. Gregory Guillot, Commander, NORAD and U.S. Northern Command, said in a news release.

Sunday’s incident took place as Trump finished a round of golf at his West Palm Beach golf course. Jets also conducted an intercept on Saturday morning shortly after Trump arrived at the course from his private Mar-a-Lago club and residence.

Trump’s schedule was not affected over the weekend, officials said. 

The Associated Press contributed to this report.