Immigration advocates last week appealed for international help to fight the Trump administration’s policy of separating immigrant parents and children who cross the United States-Mexico border.

A coalition of Texas-based rights groups filed an emergency request on Thursday (May 31) with the Inter-American Commission on Human Rights (IACHR)—a branch of the Organization of American States—to end the “systematic” and “unjustifiable” practice and reunite families that have been separated.

The request reads:

The United States government is violating internationally-recognized human rights and well-established Inter-American standards, including the rights to family, to seek asylum and protection, to minimum due process, among others, and the practice has caused a serious and urgent situation presenting a risk of imminent and irreparable harm to petitioners. The Commission should adopt precautionary measures to prevent such harm.  

In early May, Attorney General Jeff Sessions unveiled a “zero tolerance” policy regarding border crossings during a speech in San Diego, announcing that parents crossing the border would be prosecuted—an effort to deter immigrants, mostly Central Americans fleeing violence, from reaching the U.S. 

“If you cross this border unlawfully, then we will prosecute you. It’s that simple,” he said. “If you are smuggling a child, then we will prosecute you and that child will be separated from you as required by law.”

Since the May announcement, the Trump administration has separated at least 658 children from their parents, according to Human Rights Watch. Parents are prosecuted for entering the U.S. illegally and children are sent to the Office of Refugee Resettlement (ORR), a division of the Department of Health and Human Services.

The Texas-based groups that filed the request last week say its the only effective recourse they have available to challenge the systematic separations of parents and children, who are often separated without notice or information about the minors’ whereabouts.

The coalition—made up of the Texas Civil Rights ProjectWomen’s Refugee Commission, the University of Texas School of Law, and the McAllen, Texas-based Garcia and Garcia law firm—represents five parents and their children. They urge the IACHR to adopt “precautionary measures,” a mechanism designed to secure a quick action by the international body, to stop the humanitarian crisis at the U.S.-Mexico border. 

The coalition says the next step is for IACHR to tell the U.S. Department of State that it is investigating the case.

“What the commission does is say [as a member nation], ‘We’re adopting these precautionary measures, and we’re requiring you to do X, Y, Z,’” Zenén Jaimes Pérez, of the Texas Civil Rights Project, one of the organizations that filed the request, told the Texas Tribune. “Even if the United States doesn’t comply with whatever order the commission makes, in the process of doing this we can start reviewing more information about what is actually happening with separated children and all of the other details a lot of folks are in the dark about.”