Mexican authorities have arrested three more people in the fatal shootings last month of nine members of a U.S.-Mexican Mormon family that investigators have blamed on drug cartels.
A joint operation involving multiple security forces led to Sunday’s arrests in an undisclosed location, the federal attorney general’s office said in a statement. A fourth person was arrested last month.
Members of the LeBaron family ― three women and six children ― were gunned down and burned on Nov. 4 while traveling in the northern state of Sonora.
“I would imagine these are low-level people,” Julián LeBaron, a relative of the victims who is speaking for the family, told USA Today after the arrests. “We want to know who gave the order and who is responsible.”
Authorities have blamed the attack on drug cartel hit men. They haven’t commented on a motive.
The victims were members of an offshoot Mormon community that moved to Mexico from the U.S. decades ago. Days after the ambush, about 100 members of the community returned to the U.S.
President Donald Trump said in the wake of the attack that he will designate the drug cartels as terrorist groups. Mexico’s president, however, has repeatedly said he will not accept foreign pressure.
“We won’t accept any kind of intervention. We’re a sovereign, free country,” President Andres Manuel Lopez Obrador said in Mexico City’s Zocalo central square on Sunday.
Suspected cartel gunmen killed 20 people in a northern Mexican town over the weekend.
This article originally appeared on HuffPost.