A Southwest Airlines pilot was arrested Wednesday at St. Louis Lambert International Airport after security officials for the Transportation Security Administration found a loaded 9mm pistol in the first officer’s carry-on luggage.

The 51-year-old unnamed pilot was detained at the Terminal 2 security checkpoint around 4:45 a.m Wednesday, the St. Louis Post-Dispatch reported. He was arrested on suspicion of unlawful use of a weapon by local authorities after they were alerted to the incident by the TSA. The pilot was reportedly scheduled to board Flight 1106 to Las Vegas.

Police confiscated the man’s Smith and Wesson M&P Shield 9mm pistol, which TSA Spokesperson Mark Howell said was loaded with seven rounds of ammunition at the time of the pilot’s arrest. It was not clear why the pilot had the gun in his carry-on, but he did not have a permit and was not authorized to carry it.

“We are aware of a situation involving a Southwest Pilot at St. Louis Airport,” the carrier said in a statement to International Business Times. “We are currently working alongside the appropriate authorities to gather more information. We have no further information to share at this time.”

UFC champion Tyron Woodley claimed he was on the same Las Vegas-bound flight the pilot was scheduled to board and said he witnessed two individuals handcuffed at security prior to boarding.

“I get there, it’s like 5 a.m. I’m going through pre-TSA, and I see two pilots that are handcuffed,” Woodley told TMZ on Tuesday. Woodley went on to say that he thought nothing of it until he boarded the flight, which was scheduled to leave at 6 a.m. At departure time, passengers were informed they were missing flight crew needed to fly the plane, Woodley claimed.

“We found out that one of the pilots had a 9mm [pistol] or some type of gun,” he said. Woodley said passengers were compensated with $100 vouchers for the delay.

The St. Louis Post-Dispatch reported Wednesday that charges against the man are pending, and the case has been turned over to St. Louis County prosecutors.