Americans have been told to be careful when traveling in and around Mexico, in case there is a fallout from the recent arrest of two top Sinaloa drug cartel leaders.

Ismael “El Mayo” Zambada Garcia, co-founder of the Mexican Sinaloa drug cartel, and another leader Joaquín Guzmán López were arrested in El Paso, Texas, last weekend.

The Virginia-based private security firm Global Guardian has urged Americans traveling to Mexico over the next few days to “pay attention to warnings or notices from the U.S. Embassy and consulates” so they do not get caught up in street violence.

Director of intelligence Mike Ballard told Border Report: “They should maintain awareness of where they are going, especially (border cities) like Tijuana and Juarez, make sure they’re not driving into an active firefight situation.”

Meanwhile, officials from the Mexican border state of Chihuahua also issued a warning, after Chihuahua Gov. Maru Campos said folks should “prepare for the worst of scenarios in case of a spike in violence from these detentions.”

Public Safety Director Gilberto Loya said during a news conference on Monday: “Why prepare? Because it’s not clear what happened. (There could be) a different response from criminal groups if it was a surrender or a betrayal between cells of the same cartel.”

The warnings have stopped short of explicitly telling Americans not to travel in and around Mexico.

The Sinaloa drug cartel was described as “one of the most violent and powerful drug trafficking organizations in the world” by Attorney General Merrick Garland.

Both Zambada and Guzmán are facing “multiple charges in the United States for leading the cartel’s criminal operations, including its deadly fentanyl manufacturing and trafficking networks,” according to Garland’s statement.

Zambada was indicted in 2012 on murder and conspiracy charges connected with drug trafficking, money laundering and organized crime. One of his top allies and fellow Sinaloa co-founder, Joaquin Guzmán Loera, known as “El Chapo,” was convicted in federal court in 2019 after being extradited by Mexican authorities and sentenced to life in prison.

Following Guzmán’s arrest, Zambada was left as the most senior figure in the drug ring. Guzmán López, son of El Chapo, is believed to have been elevated to a leadership role in Sinaloa following his father’s arrest in 2017. Another son of El Chapo, Ovidio Guzman Lopez, was arrested in Mexico and extradited to the U.S. in September 2023.

Zambada had been pursued by the U.S. government for decades. Reuters previously reported that he was listed as a defendant in a 1978 case related to Colombian drug lord Pablo Escobar, who was shot dead in 1993.

In 2007, the U.S. Treasury Department designated a network of six companies based in Mexico that acted as fronts for Zambada. Those behind the companies included Zambada’s ex-wife, Rosario Niebla Cardoza, and the couple’s four adult daughters.