Relatives say at least five U.S. citizens, including four children, who live in a religious community in northern Mexico were killed in a shooting attack they suspect may have been a case of mistaken identity by drug cartel gunmen.
As many as 13 other members of La Mora - a decades-old settlement in Sonora state founded as part of an offshoot of The Church of Jesus Christ of Latter-day Saints - were missing after the attack on a convoy of three SUVs carrying community members, said a relative who asked not to be named for fear of reprisals.
The relative said he had located the burned-out, bullet-ridden SUV containing the remains of his nephew's wife and her four children - twin 6-month old babies and two other children aged 8 and 10.
Authorities in Sonora state and the U.S. Embassy did not immediately respond to requests for comment.
Mexico's federal Department of Security and Citizens' Protection said security forces were reinforced with National Guard, army and state police troops in the area following "the reports about disappearance and aggression against several people."
The troops were searching for the missing community members, believed to include 11 children or more.
Another relative, Julian LeBaron, said on his Facebook page the dead woman was Rhonita Maria LeBaron.
The first relative said a convoy of three vehicles had set out Monday from La Mora, about 70 miles (110 kilometers) south of Douglas, Arizona, but was attacked by cartel gunmen in a possible case of mistaken identity by gunmen. Many of the church's members were born in Mexico and thus have dual citizenship.
While he said he found the first vehicle, the other two SUVs were missing along with their passengers.
Jhon LeBaron, another relative, posted on his Facebook page that his aunt and another woman were dead, which could bring the death toll to at least seven. He also posted that six of his aunt's children had been left abandoned but alive on a roadside.
It would not be the first time that members of the break-away church had been attacked in northern Mexico, where their forebears settled - often in Chihuahua state - decades ago.
In 2009, Benjamin LeBaron, an anti-crime activist who was related to those killed in Monday's attack, was murdered in 2009 in neighboring Chihuahua state.