DJ Mustard was detained by police at Los Angeles International Airport on Friday (Dec. 8). The producer was allowed to leave, but an associate was arrested in connection with the gun.

Law enforcement officials say that Mustard and a friend were stopped by a Transportation Security Administration employee when a loaded .22 semi-automatic handgun was found in one of their carry-on bags.

According to TMZ, the two men were stopped by LAX police and questioned separately after they tried to walk away without the bag. Shortly afterwards, police were able to verify that the gun belonged to Mustard’s friend through airport surveillance. Mustard was released, but the associate was arrested.

Mustard was likely on the way to Salt Lake City for a performance at Downtown SLC. Taking to Twitter, he apologized for not making the event. He also appeared to indicate that he wouldn’t be able to make it to Spire Nightclub in Houston, where he is scheduled to appear tonight.

“Sorry to all my fans in Salt Lake City and Houston,” he tweeted. “I’ll be there soon to turn up with y’all in 2018!!!”

DJ Mustard released his Don’t Box Me remix EP in July. He is now executive producing YG’s upcoming third album, Know Your Worth, and collaborating on a joint project with RJ.