The trigger for the conflict between the two most powerful factions of the Sinaloa Cartel, a drug gang, dates to July, when legendary trafficker and leader of one of those groupings, Ismael "El Mayo" Zambada, was arrested in the United States.
Zambada, 74, alleges a senior member of the Los Chapitos, another faction of the cartel, kidnapped him and then flew him to the United States against his will.
Since fighting broke out on September 9, shootouts have disrupted daily life in the capital, Culiacan, where schools have had to close on some days while restaurants and shops shuttered early.
Sinaloa governor Ruben Rocha Moya on Friday said more than 40 people have been arrested in recent days, while more than 5000 food packages have been handed out across Sinaloa.
Mexico's military, which has struggled to calm the violence, on Thursday arrested the alleged head of security for Ivan Archivaldo Guzman, the leader of Los Chapitos and son of jailed former Sinaloa kingpin, Joaquin "El Chapo" Guzman.
Fernando Perez Medina, known as "El Piyi", was captured in Culiacan, according to a federal security source.
Meanwhile, Mexico's Federal Attorney for Environmental Protection (Profepa) said it was providing resources to local authorities to feed a tigress tied to a tree.
Senior Sinaloan narcos often keep tigers as pet animals.
Profepa said vets in Sinaloa had declined to assist due to security fears, and it had provided military officials with a "cage, a dart rifle and darts".
But the violence had prevented the military rescuing it.
Mexico's President Andres Manuel Lopez Obrador on Thursday said the United States was partly responsible for the instability because they "carried out this operation", referencing the prior surrender talks between US officials and Joaquin Guzman Lopez, the trafficker who kidnapped Zambada.
US officials have privately confirmed that they held talks with Guzman but US ambassador to Mexico Ken Salazar said in August that American officials were surprised to discover Zambada on US soil.
Salazar said no US resources or personnel were involved in the July 25 kidnapping of Zambada.
