Nazario Moreno-Gonzalez, also known as "El Chayo" or "El Doctor" was killed as part of an operation in the Mexican southwestern state of Michoacan, according to spokesman Alejandro Poire.

Poire also said that members of the federal police, army, air force and navy participated in the joint operation centered in the city of Apatzingan and the surrounding mountainous region.

Moreno-Gonzalez was one of the main leaders and founders of the drug cartel known as "La Familia Michoacana," according to Poire.

The national security spokesman said that five federal police officers and three civilians have died during the joint operation, still under way as of Friday afternoon. He also said that three members of La Familia were killed and three others have been captured.

"During the retreat and escape of these criminals, they have been picking up those members of the criminal group who have been wounded and presumably died," said Poire, who said it is too soon to provide an accurate number of deaths and arrests.

"It's time to intensify the pressure on this organization in order to diminish crime in the (Michoacan) region in an efficient and permanent way," said Poire. He said the Mexican government is sending more armed forces to the conflict zone.