Authorities believe a fierce rivalry between two Mexican drug cartels fighting for control is to blame for the massacre of nine Americans - as they investigate another fatal shootout between the gangs just hours before the Mormon family were slaughtered.

The nine LeBaron family victims, including three mothers and six children, were gunned down on Monday morning while traveling in three SUVS from the Mormon community where they live in Sonora state.

Mexican officials say the family were victims of a territorial dispute between an arm of El Chapo's Sinaloa Cartel and its Juarez Cartel rival.

Authorities believe the family may have been used to lure one side into a firefight.

They have specifically blamed the Juarez Cartel and its armed wing La Linea for the attack on the LeBaron family.

The area in Sonora state where the family was killed is dominated by a Sinaloa cartel offshoot called the Salazar.

The nine LeBaron family victims, including three mothers and six children, were gunned down on Monday morning while traveling in three SUVS from the Mormon community where they live in Sonora state

Rhonita Miller and four of her children - her six-month-old twins, Titus and Tiana, her 10-year-old daughter Krystal and 12-year-old son Howard - were all killed. Another two mothers, Dawna Langford and Christina Langford Johnson, as well as Dawna's sons, Trevor, 11, and Rogan, 3, were also all killed

Hours before the attack on the LeBaron family, La Linea sent gunmen to defend the state border area after attacks in a nearby town that were carried out by Salazar.

La Linea's gunmen had entered Sinaloa cartel territory and set up an armed outpost on a hilltop and an ambush further up the road.

Top Mexican general, Homero Mendoza, said it resulted in a shootout at about 3.15am on Monday that ended with the death of a man.

The Juarez cartel apparently wanted to send a message that it controlled the road into Chihuahua, the general said.

It was this invasion force that the American mothers and their three vehicles drove into later on Monday morning.

When the killers struck, the three LeBaron families were spread out along a 12-mile stretch of road near the border of the two states at about 9.40am.

As bullets began to pummel the first car, a white Chevrolet Suburban, Christina Marie Langford Johnson stepped out waving her arms to show that they were not gang members.

Christina was shot dead but her seven-month-old baby, Faith, survived the attack after her mother appeared to have placed her car seat on the floor before she got out.

Gunfire also ripped into a second white Suburban that was carrying Dawna Langford and nine children, about one mile back. Dawna and two of her sons, Trevor, 11, and Rogan, 3, were killed.

Footage of the vehicle showed more than a dozen bullet holes in the roof and sides of the vehicle. Inside, blood was smeared across seats and children's toys.

A third car, 11 miles behind, was shot up and burst into flames, killing Rhonita Miller and her four children - her six-month-old twins, Titus and Tiana, her 10-year-old daughter Krystal and 12-year-old son Howard.

Soldiers assigned to Mexico's National Guard stand by a bullet-riddled vehicle belonging to one of the mothers gunned down in the cartel ambush that killed nine

Emotional members of the LeBaron family look into the burned SUV where some of the nine murdered family members were killed and burned during a cartel gunmen ambush on Monday

Belongings stained with blood are seen inside a bullet-riddled vehicle that members of LeBaron family were traveling in when they were gunned down by cartel members

Police found a baby car seat spattered with blood in a bullet-riddled SUV that was being driven by one of the mothers

Devastated family members of the slain victims visited the scene of the grisly murders late on Tuesday and were pictured sobbing as they saw the burnt out and bullet riddled SUVs. Authorities were spotted hauling away the burnt wreck from the scene on Wednesday

Officials had initially said that the cartel gunmen may have mistaken the group's large SUVs for those of a rival gang. But relatives of the victims say their family was deliberately targeted and used as bait to lure one cartel against another.

'They shot us up, burned our vehicles to send a smoke signal into the sky,' one relative said, arguing that the gang's goal was to draw the Sinaloa gunmen into battle.

It was only after the third vehicle was shot up and set alight that 50 or 60 Sinaloa cartel gunmen showed up to see what had happened. Authorities and the family say heavy gun battles in the remote hill area lasted for hours into the night after the attack.

The Sinaloa and Juarez Cartels have for years been at odds over lucrative routes in the border region used to move cocaine, heroin and other narcotics into the U.S.

Mexico has unleashed its military against cartels since 2006 but despite the arrests or killings of leading traffickers, the campaign has failed to reduce violence. Instead, it has led to more killings as criminal groups fight among themselves.

A heavily armed suspected cartel hitman was arrested on Tuesday in a nearby town in a truck carrying a .50 caliber Barrett rifle and other military-grade weapons.

Criminal investigators initially said the suspect was under investigation for the massacre, but later said preliminary information indicated that he was not linked to the attack.

The Sonora state prosecutor told DailyMail.com they haven't yet ruled out his connection.

In the wake of the massacre, members of the Mexican National Guard were providing protection for the LeBaron family in Sonora state as the breakaway Mormon community prepared to hold the first funerals on Thursday.

Dozens of high-riding pickups and SUVS, many coming from the U.S., arrived overnight at the La Mora religious community in Sonora state where the victims lived.

At least 1,000 visitors were expected to arrive in La Mora, which is a decades-old settlement founded as part of an offshoot of The Church of Jesus Christ of Latter-day Saints.

Footage showed convoys of vehicles snaking their way along dirt roads as they made their way to the community as heavily armed officers guarded the route.

The funerals for Christina, Dawna and Dawna's two sons will be held near their community on Thursday.

The remains of Rhonita and her four children are due to be buried in another village called Colonia LeBaron on Friday.

Heavily armed Mexican authorities on Wednesday guard a caravan of friends and relatives of the LeBaron family as they arrive at the site where their family were killed

Mexican authorities helped guard the route leading to where the family was killed so their relatives could visit and mourn on Wednesday

National Guard soldiers were assigned to stand guard outside the homes of the victims on Wednesday to protect their families

Members of the National Guard are pictured standing guard near the homes belonging to the LeBaron families on Wednesday

'Americans should hold on to their guns': Bride-to-be whose family was killed in massacre days before her wedding advocates for carrying weapons A relative of the Mormon family slaughtered in Mexico just days before her wedding has advocated for carrying guns because she says defenseless Mexicans can't fight back against cartel gunmen. Kendra Miller, whose sister-in-law was among the nine LeBaron family members gunned down in Sonora state on Monday, claims her family was specifically targeted to wage a war between rival cartels. Speaking from her home in La Mora, where she is due to get married next week, Miller told CNN that her family constantly face threats from the cartels. Kendra Miller, whose sister-in-law was among the nine LeBaron family members gunned down in Sonora state on Monday, claims her family was specifically targeted to wage a war between rival cartels Miller brought up the issue of gun control and urged Americans to fight against any bans on weapons. 'I don't know where you're standing on the whole (idea of) trying to take away the guns in America right now, but I say fight for those guns,' she said. 'These things are happening here in Mexico because people can't protect themselves because by law they're not allowed to own these guns. 'So since the government isn't doing their job of protection in the way that they should, these cartels can just wreak havoc and the people are left defenseless. 'So I say hold onto your guns, people.' She said the issue of safety doesn't just effect her family and is part of a country-wide problem. 'What's happening here is the Mexican people are being oppressed. They're being abused by these cartels, living in fear for their life,' Miller said. 'We can't drive public roads safely. We're being threatened that we can't even take some of the public roads or else we'll have bad things happen to us. 'So many people are not protected the way that they should be.' Advertisement

At the time they were attacked, the mothers were driving in separate vehicles with their children from the La Mora religious community where they live. It is a decades-old settlement in Sonora state founded as part of an offshoot of The Church of Jesus Christ of Latter-day Saints.

Eight children, some just infants, survived the ambush.

Those surviving children not only escaped the drug cartel gunmen who killed their mothers but managed to hide in the brush for hours until help arrived.

The five wounded children were seriously enough injured that Mexican authorities flew them to the border in a military helicopter to receive hospital care in the United States.

Three other children who were not wounded are in the care of family members in La Mora.

In the aftermath of the tragedy, harrowing and heroic details emerged of the attack including how Dawna's quick-thinking 13-year-old son Devin covered his injured siblings with branches to hide them before walking 13 miles to get help from relatives back at La Mora.

Relatives say he reached the community six hours later. Family members alerted authorities before arming themselves with guns to go out searching for the injured children.

Christina has also been credited with saving her children's lives after she stashed her seven-month-old baby Faith on the floor of her Suburban and got out of the vehicle, waving her arms to show the gunmen she wasn't a threat.

She may have moved away from the vehicle to distract their attention because her bullet-ridden body was found about 15 yards away from the SUV.

The baby was found unharmed and still in her car seat on the backseat floor of the SUV when family members arrived at the scene hours later. She has since been reunited with her father Tyler Johnson.

What the children went through in the remote, mountainous area of Sonora state is nearly indescribable.

Kendra Miller, a relative, said in an account of the shootings that Devin Langford, 13, was one of the few uninjured young people and quickly took charge, eventually walking about back to La Mora for help.

'After witnessing his mother and brothers being shot dead, Devin hid his six other siblings in the bushes and covered them with branches to keep them safe while he went for help,' according to the account.

'When he took too long to return, his 9-year-old sister left the remaining five to try again.'

That girl, Mckenzie Rayne Langford, walked for hours in the dark before she was found several hours after the other children were rescued. She was listed as missing for a while.

Altogether, the kids were on their own from about 1pm, when the ambush began, until about 7.30pm, when they were rescued.

Relatives from La Mora tried to reach them before that, but were turned back by gunfire. The area is the site of a cartel turf war.

In recordings of calls between the rescuers, they can be heard debating whether it was better to risk more lives, or wait for an hour or two until Mexican army troops arrived. It was an agonizing decision.

What they saw when they found the children was terrifying.

Dawna's eight-year-old son Cody Greyson Langford had been shot in the jaw and leg. Her 14-year-old daughter Kylie was shot in the foot and four-year-old Xander was shot in the back.

Brixton, a nine-month-old, suffered a gunshot wound to the chest. Her son Jake was found injured in the same spot but it's not clear what his injuries are.