MEXICO CITY, Nov 24 (Reuters) - The head of Mexico's National Guard in the state of Zacatecas was killed on Thursday in a confrontation with armed men during an operation against organized crime, authorities said.General Jose Silvestre Urzua, one of the highest-ranking commanders of Mexico's militarized police force and the head of its Zacatecas branch, died fulfilling his duties, Security Minister Rosa Icela Rodriguez said on Twitter.The central state of Zacatecas has become one of Mexico's most violent places because of conflicts between criminal gangs over drug trafficking.Last month, lawmakers approved extending the role of the armed forces in public security until 2028 in an effort to curb violence.President Andres Manuel Lopez Obrador backed the creation of the National Guard after coming to power at the end of 2018, looking to fight organized crime and end endemic police corruption in its predecessor, the federal police."