Mexico has replaced all 700 of its customs inspectors with agents newly trained to fight drug smuggling.
Soldiers have been sent to airports and border crossings throughout the country to take back the guns issued to the inspectors.
Tax service spokesman Pedro Canabal said the officers were not fired. Instead, the agency decided not to rehire them when their contracts expired over the weekend.
They were replaced with 1,400 new agents who have undergone months of training and background checks.