Transportation Security Administration officers found a loaded gun in a passenger’s carry-on bag at the Charleston International Airport on Friday, spokesman Jon Allen said.

The .22-caliber pistol was discovered about 5 a.m. during a security checkpoint, Allen said. The gun’s owner intended to fly to Philadelphia but was arrested instead.

Passengers are urged to check their bags for illegal or prohibited items before coming to the airport, Allen said.

Passengers are allowed to travel with unloaded firearms that are properly packaged and declared. Guns must be packed in a hard-side case, locked and carried separately from ammunition, Allen said.

Last year, TSA officials found 1,556 firearms at checkpoints nationwide and assessed more than $1.8 million in civil penalties for such cases, Allen said.