Nine US citizens were killed on Monday when their vehicles were ambushed by gunmen in northern Mexico, officials said on Tuesday. The victims – three women and six children – were members of a fundamentalist Mormon sect that has been based for many decades in a remote stretch of Mexico about 240km (150 miles) southwest of El Paso, Texas. At a news conference on Tuesday morning, Mexican Security Secretary Alfonso Durazo said that the group was ambushed by unknown assailants as they travelled in a caravan of three vehicles from the town of Galeana, Chihuahua, to Bavispe, Sonora. Durazo said that Mexican security forces found six other children and another woman who fled the attack and that another minor was still missing. The six children and woman who were found were all injured, he said, with one child suffering a gunshot wound to the back. ....monsters, the United States stands ready, willing & able to get involved and do the job quickly and effectively. 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! — Donald J. Trump (@realDonaldTrump) November 5, 2019 Durazo and Mexican President Andres Manuel Lopez Obrador said the motives of the attack were unclear. “It’s been a very violent area for a long time,” Lopez Obrador said. “We’re going to wait to see what the investigations say about what actually happened.” On Tuesday morning, US President Donald Trump tweeted angrily about the ambush. “A wonderful family and friends from Utah got caught between two vicious drug cartels, who were shooting at each other, with the result being many great American people killed,” he wrote. Mexico captures El Chapo’s son – and then releases him amid gun battle Trump said the US was ready to assist “if Mexico needs or requests help in cleaning out these monsters”. “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,” the president tweeted. His response was sure to ruffle feathers in Mexico, where Lopez Obrador has repeatedly insisted he does not want war with Mexico criminal groups, saying the militarised strategy of his predecessors turned Mexico into a “graveyard”. In recent weeks, amid criticism from other US officials that Mexico does not have a cogent security strategy to fight rising violence, Lopez Obrador said that the US must respect Mexico’s sovereignty and that “officials from other countries should not offer opinions about internal issues that only concern our government”. Monday’s massacre is the latest in a string of extreme violent incidents in Mexico that have thrown the Lopez Obrador administration into crisis. Last month, 13 people were killed in a botched federal operation to capture a leader of the Sinaloa drug cartel in the city of Culiacan. Mexican forces decided to release the leader, Ovidio Guzman, after the cartel laid siege to the city for several hours. Earlier in the month, 14 state police officers were ambushed and killed in Michoacan state. In August, the bodies of 19 people were hung from a bridge and dumped nearby in another city in Michoacan. Also that month, 27 people burned to death when criminals firebombed a strip club in Veracruz, allegedly after its owners failed to produce extortion payments. The region where Monday’s massacre took place has long been lawless. ‘Overwhelming evil’: drug lord El Chapo sentenced to life in US prison It is a highly remote mountainous region that is mainly disputed by two criminal organisations: the Sinaloa cartel and La Linea, a criminal group related to the Juarez cartel. The Mormon presence in the region dates back to 1886, when the Church of Jesus Christ of Latter-day Saints began cracking down on polygamists and a sect that embraced that tradition fled the US and bought 50,000 acres of land in the Mexican state of Chihuahua along the Piedras Verdes river. In 1944, a member of that community, Dayer LeBaron, acting on what he said was a message from God, relocated his family about 56km (35 miles) south and established a breakaway Mormon community known as Colonia LeBaron. The sect has a tumultuous and sometimes violent past. In 1993, a federal jury in Texas convicted three members of an offshoot of the community in the slayings of three former members and an eight-year-old child. In more recent years, the group has had repeated conflicts with locals over natural resources – primarily water rights – and has been victim to organised crime. In 2009, armed assailants captured and killed Benjamin LeBaron, a leader of the group and a great-grandson of its founder. LeBaron, a US citizen, had led anti-violence protests after his teenage brother was kidnapped and held for US$1 million ransom. The family refused to pay the ransom and the teenager was eventually released. Members of the community, whose apple and pecan farms are located on a drug and migrant smuggling route that leads into the United States, have long been proponents of looser gun laws in Mexico. After a rash of violence in the region several years ago, the government allowed the group to form an armed citizens patrol.