Mexico City, Feb 22 (Reporter) At least 12 people were killed in a confrontation between rival criminal gangs in Mexico's southern state of Guerrero, President Andres Manuel Lopez Obrador said on Wednesday. Investigation into the incident began Tuesday and is ongoing, with National Guard troops already at the site, Lopez Obrador told reporters at the National Palace in Mexico City at a daily press conference. The president said the authorities will provide more details later on the deadly clash, according to local media...////...