A suspect holding two bound and tied hostages in a vehicle has been arrested in the massacre of nine US citizens – three moms and six children – at the hands of drug cartel members in Mexico, officials said Wednesday.

The unidentified suspect — who was found on Tuesday in the town of Agua Prieta, which borders Arizona – also was in possession of four assault rifles, ammunition and several large vehicles, including a bullet-proofed SUV, according to the Agency for Criminal Investigation for the state of Sonora.

“We are waiting for some more intelligence in order to issue an official statement,” the attorney-general for the neighboring state of Chihuahua, Cesar Peniche Espejel, told Mexico’s Imagen Radio, according to CNN.

The attackers may have mistaken the doomed group’s SUVs for those of a rival gang as the three families from a Mormon community were slaughtered Monday along a rural road between Sonora and Chihuahua.

The victims, dual US-Mexican citizens, were apparently members of a fundamentalist sect separate from the mainstream Church of Jesus Christ of Latter-day Saints.

Eight children, some just infants, survived the carnage by hiding in the brush, with some walking several miles to seek help despite their severe injuries.

Peniche Espejel said he believed the “Los Jaguares” cartel — an off-shoot of the Sinaloa cartel — may be responsible for the atrocity, according to CNN.

On Tuesday, a US official said a rival cartel, La Línea, is under focus.

“These very cartels of Sinaloa, after the arrest of Guzman ‘El Chapo’ have suffered fragmentations,” Peniche Espejel said. “They have been growing near the border with the United States and are heavily involved in trafficking of immigrants into the United States and drug-trafficking.”

All of the victims are believed to have been members of the extended LeBaron family, which settled in Sonora decades ago, after the Mormon church in Utah banned polygamy.

Former Foreign Minister Jorge Castañeda told CNN that the family may have been targeted because of its history of conflict with Mexican drug cartels.

“They had stood up to the drug cartels and they did have certain frictions either with the cartels or with neighboring communities over water rights,” said Castañeda, who left office in 2003.

“Their long-standing tensions, and apparently the woman who was driving in the first car that was attacked was an activist. She was someone who was very active in her community, defending her family, her fellow members of the community against cartels, on the issue of water rights,” he said, describing one of the three women killed.

Castañeda also said the larger LeBaron community had been protected by 90 federal police since 2011 because of tensions between the family and cartels.

That protection was withdrawn to some degree by the current government this year, he said, adding that it was unclear whether all 90 officers were withdrawn or just some of them.

Security Minister Alfonso Durazo said Tuesday that the attack may have been a case of mistaken identity of “conflicting groups in the area.”

But Castañeda told the network that he considered that theory unlikely, especially because two vehicles in two different locations carrying members of the same family were attacked in the same manner.

On Wednesday, Alfonso Durazo, a public security official, said preliminary information indicated the suspect was not linked to the attack. He did not immediately provide any additional details.