U.S. fighter jets intercepted two civilian aircraft Sunday after they entered temporarily restricted airspace over Bedminster, New Jersey, where President Donald Trump was attending a golf tournament at his private club, military officials said.

F-16 fighter aircraft operated by the North American Aerospace Defense Command responded to the separate airspace violations on Aug. 9 and safely escorted both general aviation aircraft out of the restricted area. No injuries or other incidents were reported.

NORAD did not say what types of aircraft were intercepted or identify the pilots. The command also declined to determine whether the violations resulted from pilot error, saying that decision would fall to the Federal Aviation Administration.

Temporary flight restrictions were in place around Bedminster as Trump attended the LIV Golf tournament at Trump National Golf Club. The president was scheduled to return to Washington later Sunday.

NORAD reminded civilian pilots that they are required to check current Notices to Airmen and FAA temporary flight restrictions before departure. Pilots intercepted by military aircraft are instructed to immediately monitor emergency frequencies 121.5 or 243.0 MHz, reverse course and follow additional instructions from the intercepting aircraft.

Sunday’s incidents follow several previous airspace violations in the region during presidential travel and major events.

On July 19, more than 10 general aviation aircraft entered temporary flight restriction zones over Bedminster and East Rutherford, New Jersey, according to NORAD. Three aircraft required fighter intercepts, and F-16s deployed flares during two encounters to attract the pilots’ attention. All of the aircraft were safely escorted from restricted airspace.

NORAD said the flares used during such intercepts burn out quickly and are deployed with safety precautions intended to prevent danger to people on the ground.

The Continental U.S. NORAD Region, headquartered operationally at Tyndall Air Force Base in Florida, oversees the mission responsible for responding to such violations.

Authorities have not indicated that either of Sunday’s aircraft posed a deliberate security threat, and no information has been released suggesting hostile intent.