The American Civil Liberties Union is suing the Trump administration for separating a 7-year-old migrant from the Democratic Republic of Congo from her mother.
The girl, called S.S., is in detention in Chicago, while her mother, Ms. L, remains in custody 3,200 kilometers away in San Diego. They have spoken by telephone only a handful of times.
The ACLU called the separation a "flagrant disregard of the Constitution and common sense" and is suing for their release from custody or their reunification in a family detention center.
"The government has no legitimate interest in separating Ms. L from her daughter since there's been no evidence or even accusation of abuse or neglect," the group said Monday.
It said the mother and daughter arrived in San Diego seeking asylum from violence in the DRC, fearing for their lives if forced to go back.
The ACLU contends they were separated five days later without any explanation, and that both mother and child were terrified, knowing no one and having no idea what would happen to them.
The lawsuit contends the pair's constitutional rights were violated because they were split up without a hearing.
The ACLU also says the separation could have lasting psychological harm on the child.
The Department of Homeland Security does not comment on individual cases or pending lawsuits.
Tom Homan, acting head of the Immigration and Customs Enforcement agency, told The Associated Press last month that many migrants who seek asylum in the United States have weak claims that are ultimately thrown out by judges.
"I'd be a fool to say that none of them have a case of credible fear. They're really escaping danger," he said. "But I can tell you — many of them are taking advantage of a low threshold."