El Chapo Guzman in a US jail as El Mayo and Sinaloa cartel fight CJNG

Former Sinaloa cartel kingpin Joaquin “El Chapo” Guzman is in a Manhattan jail awaiting what will almost certainly be a life sentence in one of the US’s most secure prisons.

Since his capture in early 2016, Mexico’s criminal groups have fought on, and the cartel he founded and its rivals now appear to be opening a new phase in their battle for dominance.

Read more: The rise and fall of Joaquín ‘El Chapo’ Guzmán, the world’s most ambitious drug lord

Less than two weeks after Guzman was found guilty, at least five narcomantas — banners conveying messages from criminal groups — were found in Guadalajara, Mexico’s second-largest city and the capital of Jalisco state, a stronghold of the Sinaloa cartel’s main rival, the Jalisco New Generation cartel.

The same message appeared on all the banners, according to a report by Mexican news outlet Proceso, announcing the start of a “cleansing” in Mexico, supported by the government, and promising the return of “the old school” — likely referring to the “old guard” of drug traffickers, of whom Ismael “El Mayo” Zambada is one of the few still alive and free.

The Guadalajara banners were attributed to Zambada, whose name appeared on them. Those and other banners with similar messages have been seen as indications Zambada wants to impose new order on the criminal underworld.

Read more: The US got ‘El Chapo’ Guzman — now it has to get his $14 billion

In Sinaloa state, banners attributed to Zambada appeared with the message: “Either line up or I’ll line you up.”

Zambada, who has never been captured, was Guzman’s peer at the top of the Sinaloa cartel and is now believed to be running the it alongside Guzman’s sons, after they triumphed in a months-long internal fight for control.

Days after the banners appeared in Guadalajara, the brother of Damaso Lopez Nuñez, Guzman’s right-hand man before being captured and testifying against him, was killed in Sinaloa state.

“The Sinaloa cartel is conducting retribution against Damaso’s relatives for the attempted assassination of Mayo and Chapo’s sons,” Mike Vigil, former chief of international operations for the US Drug Enforcement Administration, told Business Insider in March, referring to a 2017 incident in which Zambada and Guzman’s sons accused Lopez of inviting them to a meeting and attempting to kill them.

“The other thing too is that the Sinaloa cartel is trying to basically wipe out the Jalisco New Generation cartel … and there’s an internal insurrection within the Jalisco New Generation cartel,” Vigil said, in reference to a group in Guadalajara called the Nueva Plaza cartel, which is believed to be challenging CJNG with the backing of its rivals, including the Sinaloa cartel.

Read more: Mexican troops are in the streets to fight the drug war, and the country’s former defense chief says legalization may be ‘a way out’

“The Sinaloa cartel is taking advantage of that insurrection, as well as the fact that the Mexican government is really pursuing” CJNG leader Nemesio Oseguera Cervantes, aka “El Mencho,” said Vigil, noting that the Sinaloa cartel’s maneuvers were “not necessarily” related to Guzman’s conviction. The CJNG has also attracted special attention from authorities because of its propensity for violence.

The Jalisco cartel has not let this go without a response. On March 5, another narcomanta was found on a footbridge in Tijuana with a message directed at Zambada. It said the city “is not your plaza” and was signed by people claiming to be members of the Tijuana New Generation cartel, which has partnered with the CJNG to contest the Sinaloa cartel’s control of Tijuana and its valuable cross-border smuggling routes.

On March 31, another narcomanta was found with two bodies in the city of Aguascalientes, capital of the small central Mexican state of the same name.

According to media reports, the banner and the bodies, which showed signs of torture, were meant as a message from the Sinaloa cartel to the CJNG.

Read more: Violence is high in Mexico’s most popular tourist destinations — but some groups are more at risk

According to the reports, one of those found dead was the main drug distributor in a residential neighborhood in the city — another sign the feud between the two cartels, both of which have focused on transnational drug smuggling, could be developing into a fight over street-level drug sales as well.

Fighting for those sales has been blamed for increasing violence in Mexico, particularly in Tijuana and Ciudad Juarez, as well as Mexico City.

‘His days are numbered’

Zambada is believed to have run the Sinaloa cartel alongside Guzman since its emergence in the 1990s. (Guzman’s defense team argued Zambada was really the top capo.)

Zambada and Oseguera now appear to have established themselves atop of Mexico’s narco hierarchy. Though Zambada may be attempting to exercise his clout on other groups, the stability of his own is not assured.

“I think if I were Mayo I would be keeping my eye out and exert a tremendous amount of authority on the Sinaloa cartel to prevent internal insurrections,” which has to be one of his concerns, Vigil said.

Read more: The FBI just put the ‘narco of narcos’ on its 10 Most Wanted list

Zambada is believed to be about 70, older than Guzman, and is thought to be in poor health, suffering from diabetes, Vigil said. His age and health — along with the relative inexperience and impetuousness of Guzman’s sons, presumably the next in line for control — are issues of which rivals and partners alike are aware.

“He doesn’t have access to good medical care, being up in the mountains” of northwest Mexico, Vigil said.

“So I think his days are numbered, and when that happens … Chapo Guzman’s sons really have never gotten their hands dirty. They were just thrust into the upper ranks of the cartel,” Vigil said. “I personally think they’re incapable of running the cartel, and they don’t have the respect of the rank and file.”

With Guzman’s sons at the helm, “then you’re going to see the Sinaloa cartel diminish in terms of stature and in terms of capabilities, and [it] will definitely fracture … [and] have forces within that will break off,” with the sons and Guzman’s brother trying to control as much as they can, Vigil said.

“It’s not going to be as powerful as it is now. It’s going to disintegrate” much like the Zetas or the Gulf cartel did in the face of increased pressure and after important leaders were taken out.

Uncertainty about the future doesn’t mean business is hurting. The Sinaloa cartel, which has always functioned more like an alliance of factions rather than a traditional hierarchical organization, has been resilient, thriving off the cocaine trade and, more recently, off heroin and synthetic drugs.

Read more: How Mexico’s fearsome Zetas went from a powerhouse cartel to a weakened group of rival factions

The cartel is believed to control swaths of opium-producing territory in Mexico, and a “cook” in northwest Mexico told Sinaloa-based news outlet Rio Doce in late 2017 that heroin production had expanded dramatically.

Mexico’s west coast, along which the Sinaloa is oriented, is valuable for cartels bringing in precursor chemicals needed to make drugs like methamphetamine. Violence in Pacific coast port cities has been blamed on fighting for control of that region. Labs making synthetic drugs have been busted repeatedly in Sinaloa state in recent years.

Mexican cartels continuing attention to US drug use was illustrated in early April, when the first lab in Mexico known to produce fentanyl, a highly potent synthetic opioid, was found in a home in Culiacan, Sinaloa’s state capital.