Among the crimes allegedly committed with the weapons were the slayings of two migrant protection officers in Tijuana last month, the San Diego Union Tribune reported Tuesday.

Last weekend's gun battle left as many as 15 members of rival drug gangs dead and eight wounded, authorities said. Police have rounded up 10 suspects, including Andrew Armando Cordova, a 21-year-old U.S. citizen from Los Angeles, the Baja California Attorney General's Office said.

Gang and drug violence in Mexican border towns has prompted President Felipe Calderon to send thousands of troops to cities along the border to help local authorities.