Investigators are trying to piece together a horrific ambush on Monday in Northern Mexico. More than twenty people were driving to a wedding when they were stopped and shot. The Utah family is part of a community of Mormons living in Mexico.

NBC writes:

“At least nine U.S. citizens, including six children, were killed in a massacre in the Mexican border state of Sonora Monday, a relative to many of the victims told NBC News.

The dead included 8-month-old twins, said the family member, Kendra Lee Miller. Some of the eight survivors, all of whom are children, sustained serious injuries. Miller said a 9-month-old child was shot in the chest and a 4-year-old was shot in the back.”

The Washington Post adds:

One vehicle, driven by Maria Ronita LeBaron, had a flat tire, and the others turned back to get help, according to the reports. The assailants attacked the first car, killing the driver and her four children — including two 6-month-old twins, according to the reports. They then set the vehicle on fire.

When the rest of the group returned to the site in two vehicles, they were also ambushed, the reports said. Several other children escaped.

Vice says, “It was not clear if the family, which has spoken out against cartels, was targeted, or if it was a case of mistaken identity.” But Donald Trump is telling a different story on Twitter.

Watch more from CBS above.