One of the victims is believed to be Rhonita Maria LeBaron and four of her children - her six-month-old twins, Titus and Tiana, daughter Krystal, 10, and 12-year-old son Howard - were all killed.
Mum Christina Langford is also believed to have died but her daughter Faith, seven months, is said to have survived after Christina shielded her from bullets.
Another mum Dawna Langford was also killed alongside her sons aged 11 and three.
The group of mums and kids were said to be travelling in convoy of three SUVs on a dirt road in northern Mexico. They were driving from La Mora religious community where they live, which is an offshoot of the The Church of Jesus Christ of Latter-day Saints.
They are thought to be dual US Mexican citizens, many people living in the community are from the USA but live in Mexico.
It's thought Rhonita was driving to the airport to pick up her husband, who'd been on a work trip, when she got a flat tyre. Rhonita returned to the religious community to change cars and when she left the other women followed as they were on their way to a family wedding in another town.
All three women were in their own cars with their children and it's believed the convoy may have been mistaken for a rival drug cartel, as there is currently a turf war taking place in the region.
There cars were found over an 11-kilometre stretch and it's thought one of the cars was fire bombed and burnt out while the rest were shot at and found riddled with bullets.
Eight children are believed to have survived but six children were wounded in the attack and five have since been transferred to hospitals in Phoenix, Arizona, USA.
In a series of tweets, President Trump aid the families had been caught up between 'two vicious drug cartels'.
He added: ‘The great new President of Mexico has made this a big issue, but the cartels have become so large and powerful that you sometimes need an army to defeat an army.
‘This is the time for Mexico, with the help of the United States, to wage war on the drug cartels and wipe them off the face of the earth.’