SAN DIEGO — Two U.S. Army reservists in San Diego County were arrested Wednesday and charged with illegally selling guns, ammunition and body armor to an undercover federal agent posing as a member of a Mexican drug cartel.

According to a criminal complaint, Jaime Casillas, 22, and Andrew Reyes, 34, sold 10 guns, including four AK-47 assault rifles, and thousands of rounds of ammunition to the undercover agent. The complaint says some of the arms were military issue and others were bought in Texas and resold in California.

They were sold in seven different meetings with the undercover agent, who made it clear on multiple occasions that he worked for a cartel and the guns were bound for Mexico, the complaint said. The agents wore their military uniforms to at least one of the exchanges.

Reyes indicated that the body armor and ammunition magazines they sold were from military inventory, the complaint said.

The reservists got at least $13,000 from sales to the undercover agent.

Both men work in the Army National Guard Armory in La Mesa and were arrested Wednesday — Casillas during a traffic stop in El Cajon and Reyes at his home in La Mesa.

They were indicted on charges of dealing firearms without a license and the unlicensed transport of a firearm.

Contact information for attorneys or associates of the men was not immediately available. The two are scheduled to appear in court Thursday.