Mexican authorities are investigating after six human heads were located near the border between two states in the country this week.

The Tlaxcala State Attorney General's Office, the agency investigating the case, announced the discovery on Aug. 19 in a news release.

The severed heads were discovered on a road between the Mexican states of Puebla and Tlaxcala. The area is east of Mexico City in the country's central region.

According to the release, police officers and experts with the Institute of Forensic Sciences responded to the scene to investigate the deaths, which involved all males. The victims' ages and where they lived were not provided.

Prosecutors did not share the date or exact location where the remains were discovered but said, "It should be noted that the location corresponds to the discovery, not the actual incident."

Local outlet La Jornada reported someone called 911 about 6:45 a.m. local time about "what appeared to be a human head, on the side of the road."

According to information from the outlet and the BBC, one head was found with a banner with a name attributed to a criminal group: "La Barredora."

Translated from Spanish to English, it means "the sweeper."

Who do the human heads found in Mexico belong to?

As of Aug. 20, local authorities had not released the victims' identities.

A motive in the case was not immediately known.

Prosecutors said they are working to determine who killed the victims, clarify what happened and hold accountable those found responsible.

'A bold bilateral initiative' launched by DEA

The announcement came the same day Mexico's President Claudia Sheinbaum announced the country's government did not have an agreement with the U.S. Drug Enforcement Administration (DEA) over an operation called "Project Portero," Reuters reported.

Sheinbaum's announcement, according to the outlet, came one day after the DEA said in a statement it was launching a "bold bilateral initiative with Mexico aimed at dismantling drug smuggling corridors."

"The DEA issued this statement; we do not know on what basis. We have not reached any agreement through any of the security agencies with the DEA," Sheinbaum said during a news conference. "We do not know why they put out this statement."

The move also came the same day Boxer Julio César Chávez Jr. was deported to a jail in Mexico after his arrest by U.S. Immigration and Customs Enforcement. He was being held at a prison in the northern Mexican state of Sonora, according to the country's national arrest registry.

Chávez Jr. is facing allegations that he acted as a henchman for the Sinaola cartel, a recently U.S.-designated terrorist organization. His arrest came four days after losing a boxing match to celebrity boxer Jake Paul.

The discovery of the heads also came after Mexico, last week, shipped 26 suspected cartel members to the United States amid a push from President Donald Trump to dismantle the country's powerful drug organizations.

Authorities sent prisoners wanted in the United States in connection with drug-trafficking ties, according to Mexico's attorney general's office. Country leaders said the U.S. Department of Justice had requested their extradition and would not seek the death penalty for the charged cartel members.

It was not the first time Mexican authorities sent prisoners to the United States for similar reasons. In February, officials sent more than two dozen alleged cartel members over the border.

Contributing: Josh Meyer, USA TODAY; and Reuters

Natalie Neysa Alund is a senior reporter for USA TODAY. Reach her at nalund@usatoday.com and follow her on X @nataliealund.

This article originally appeared on USA TODAY: 6 severed human heads found in central Mexico, state prosecutors announce

Reporting by Natalie Neysa Alund, USA TODAY / USA TODAY

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