Officials at Joint Base Andrews say they are investigating after a man gained unauthorized access to an aircraft parked on base Thursday.

The military facility, located in Maryland right outside Washington, D.C., houses aircraft used to fly top U.S. officials, including Air Force One, which transports the president.

According to an emailed release from base officials, the man entered a C-40 aircraft, a military version of a Boeing 737-700 thats often used by members of the Cabinet and Congress. The unidentified individual was detained and questioned by Joint Base Andrews security officials and the U.S. Air Force Office of Special Investigations, and given a federal summons for trespassing. Then he was turned over to local law enforcement, who took him into custody on two outstanding warrants.

Officials said that the man, who was unarmed, didnt appear to have any links to extremist groups.

The security of our installation is paramount, Col. Roy Oberhaus, the vice wing commander of the U.S. Air Force 316th Wing at the base, said in the release. This was a serious breach of security and Joint Base Andrews is investigating the incident to determine how this happened so it doesnt happen again.

In a related move, Joint Base Andrews temporarily suspended its Trusted Traveler Program late Thursday. A spokesperson told Air Force Magazine that the program allows people with certain levels of access to the base to vouch for other people riding in the same vehicle, rather than requiring that they be pre-approved to visit the installation.