Gunmen hijacked two trucks hauling more than seven million rounds of ammunition in central Mexico, a massive heist that could escalate fighting in one of the country’s most violent areas. The armed group intercepted the trucks on June 9 in the municipality of San Luis de la Paz, in the central state of Guanajuato, according to press reports. The drivers and security personnel were unharmed in the robbery. The trucks were found later, with their two trailers emptied of bullets.