MEXICO CITY — Gangland-style murders are a daily event in Culiacán, the capital of Mexico’s Sinaloa state, where businesses close early, schools suspend classes and people must take precautions to avoid getting caught in the crossfire.

The extradition of Mexican drug kingpin Joaquín “El Chapo” Guzmán to the United States in January was supposed to curb the violent drug wars raging south of the border. Instead, rival factions of Guzmán’s organization have ignited a new deadly turf war for control of the drug lord’s rudderless empire.

“It is a nightmare but one we have lived many times before,” said Rosita Méndez, a mother of two young children who lives in Culiacán.

Mexican Defense Secretary Salvador Cienfuegos acknowledged at a recent news conference here that Guzmán’s criminal organization “is fighting an internal struggle for control of the organization due to the absence of its leader.”

A rival faction within the cartel headed by a former lieutenant of El Chapo, former state police official Dámaso López, aka “El Licenciado” or “the Graduate,” is believed to have killed Guzmán’s sister and wounded his two adult sons in a shootout in western Mexico earlier in February.

“It appears that we are seeing a generational transition from El Chapo to his sons,” said Alejandro Hope, an independent security expert in Mexico City. “It is the greatest such power shift within the organization for many years, and all hell is breaking loose.”

The violence in Sinaloa, a mountainous region dubbed “the cradle” of Mexico’s drug trade, contributed to 2,152 killings nationwide in January, the most in the country in the last 20 years, according to government statistics.

They were the latest casualties in a drug war that has claimed more than 100,000 lives since former Mexican president Felipe Calderón announced a federal crackdown on the cartels in 2007. Almost 21,000 murders occurred last year — a 20 percent increase from 2015.

Amid the bloodshed, El Chapo’s adult sons, Alfredo and Archivaldo Guzmán, issued a rare public letter to the Mexican news media on Feb. 8 accusing López of betraying them.

In the letter, the brothers claim López called a meeting with them and another of El Chapo’s closest allies, drug lord Ismael “El Mayo” Zambada, on Feb. 4 to calm tensions between the factions following accusations that López masterminded the kidnapping of the brothers from a glitzy nightclub in Puerto Vallarta last August. Both men were later freed after Zambada reportedly acted as negotiator.

When the brothers and Zambada arrived at the meeting with López, gunmen fired on them, killing their bodyguards and wounding the brothers, the letter said.

According to a 2011 indictment filed in a U.S. federal court in Alexandria, Va., Dámaso López is a former state police official who was working at the maximum security prison where El Chapo escaped in 2001. Leading Mexican daily El Universal reported López was later integrated into the cartel hierarchy as a trusted ally of Guzmán who became godfather to López’s son.

The Cartel of the Pacific, also known as the Sinaloa Cartel, is Mexico’s oldest major drug trafficking organization and is widely regarded as the most powerful. Throughout the 2000s, the group waged war with rivals throughout northern Mexico and had appeared to emerge as the winner of the country’s drug wars.

“One of the reasons that the Sinaloa Cartel has survived so long is a decentralized leadership structure with close personal and family ties among the top players,” said Alejandro Hope, an independent security analyst based in Mexico City. “It has enabled them to go on functioning when other organizations have collapsed.”

But that closeness appears to be disintegrating without the elder Guzmán in control.

Some analysts say the rift might further escalate. Jorge Kawas, a security risks analyst in Monterrey, said López’s faction is likely cooperating with sworn rivals of Guzmán to wrest power from the drug lord’s relatives.

“It’s suspected that López has forged an alliance with the Jalisco New Generation Cartel, a breakaway organization that once functioned as a paramilitary wing of El Chapo’s group and is now competing with them for trafficking routes and territory,” Kawas said, adding that western Mexico is a vital pipeline for marijuana, heroin and crystal meth shipments.

In January, El Chapo Guzmán pleaded not guilty in a U.S. federal court to 17 counts of drug trafficking, firearms violations and money laundering. U.S. prosecutors have also announced their intention to seize $14 billion in assets allegedly acquired through narcotics sales.

The spike in violence comes amid fraught relations between Mexico and the U.S. as President Donald Trump has threatened to withdraw drug war aid to help pay for a projected border wall. Since 2008, the United States has provided $1.6 billion in security assistance to Mexico as part of an agreement reached by then- President George W. Bush and Mexico’s Calderón.

“It’s impossible to know what to expect from Trump on drug assistance because his remarks have been vague and contradictory so far,” said Hope.

Hope and others believe Mexico has to take responsibility for failing to stop the feuding.

“We are still dealing with many of the same structural problems in Mexico, such as ineffective police and a weak justice system,” said Kawas. “Every time it appears progress has been made, we see another swell in violence.”

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