Mexican army troops have killed 19 suspected drug cartel gunmen in a shootout and suffered no casualties, the Defense Department said.

The ruling Morena party has criticized past administrations for lopsided death tolls in which many suspects but no soldiers died, suggesting they constituted executions or rights abuses.

The confrontation occurred Monday in the northern state of Sinaloa, on the outskirts of the state capital, Culiacan. The area has been shaken by infighting between two factions of the Sinaloa cartel since early September.

The department said that before the confrontation, troops detained a top lieutenant of the "Mayitos" faction, loyal to imprisoned drug lord Ismael "El Mayo" Zambada. The army did not give the name of the suspect, who they identified only by nickname "El Max."

MEXICAN NEWSPAPER OFFICES HIT BY GUNFIRE IN SINALOA STATE CAPITAL

The army then said troops were attacked by more than 30 assailants, at least 11 of whom managed to escape and 19 of them were killed when soldiers returned fire.

The Defense Department claimed soldiers acted in self-defense and "strict adherence to the rule of law and with full respect for human rights."

It said that 17 rifles — including a .50-caliber sniper rifle — as well as four machine guns were seized at the scene.

The current round of fighting broke out after Zambada claimed he was forced aboard an airplane on July 25 by another drug capo who flew them both to the United States and turned them in to U.S. authorities.

The man Zambada claimed had kidnapped him — Joaquín Guzmán López, one of the sons of imprisoned drug lord Joaquín "El Chapo" Guzman — is a leader of a rival cartel faction known as the "Chapitos."

The shootout Monday was the most lopsided confrontation since the killing of 22 suspects by soldiers at a grain warehouse in the township of Tlatlaya, in the State of Mexico, in 2014.

While some of the 22 died in an initial shootout with an army patrol — in which one soldier was wounded — a human rights investigation determined that at least eight and perhaps as many as a dozen suspects were executed after they surrendered.

Seven soldiers were arrested, freed and then arrested again years later on charges of abuse of authority.