U.S. Ambassador Ken Salazar has rejected accusations by Mexico’s president that the U.S. shares some responsibility for cartel violence in Sinaloa state.

The most recent deaths come nearly two months after officials arrested Sinaloa Cartel leader Ismael “El Mayo” Zambada in the United States. His arrest reportedly sparked infighting within the Sinaloa Cartel’s two factions: Los Chapitos spearheaded by co-founder Joaquin “El Chapo” Guzman Loera and La Mayiza led by Zambada.

Some 53 people have been killed and 51 others are missing in Mexico's western Sinaloa state since rival factions of the Sinaloa Cartel began clashing on Sept 9, local authorities said on Friday, with gruesome violence showing no signs of abating.

Mexican President Andrés Manuel López Obrador has blamed the United States in part for the surge in cartel violence terrorizing the northern state of Sinaloa which has left at least 30 people dead in the past week.

Mexican leader says the U.S. bore some responsibility "for having carried out that operation" to arrest Ismael 'El Mayo' Zambada.

Two warring factions of the Sinaloa cartel appear to be fighting for power since two of its leaders were arrested in the U.S.