(CNN) The FBI is taking part in the investigation into an attack that left nine people dead last week in Mexico near the US border.

Three women and six children, all of the Mormon faith, were shot dead in the mountains on November 4 when suspected drug cartels opened fire on a remote dirt road in Sonora state. The victims were dual citizens of Mexico and the United States.

"The FBI will be providing assistance at the invitation of the Mexican government with the investigation into the recent attack against American citizens," the FBI said in a statement. "The FBI remains committed to working alongside our international partners to help bring justice to the perpetrators of this heinous act of violence."

Mexico's foreign ministry sent an invitation to the FBI to assist in the investigation. In a statement Sunday, Mexico reiterated its commitment to investigate the facts to ensure justice to the affected families

The horrific massacre in broad daylight stunned even a country long ravaged by drug violence and on pace for a record high number of homicides this year. The convoy carrying women and children was ambushed and sprayed with hundreds of rounds of ammunition. One mother was gunned down as she begged the children be spared.

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