Immigration officials say a Mexican migrant died Monday after his arrest near an urban border crossing.

U.S. Customs and Border Protection announced the death Tuesday, saying agents arrested the 40-year-old man early Sunday for re-entering the country illegally. His identity wasn't released.

He died at an El Paso hospital after receiving treatment for flu-like symptoms and liver and kidney failure. He's the fourth migrant to die in CBP custody since December, including an 8-year-old boy and a 7-year-old girl.

Border Patrol Commissioner Kevin McAleenan said this month the system "is well beyond capacity and remains at the breaking point."

In a statement, ACLU Border Rights Center Director Astrid Dominguez said "a transparent and independent investigation into the conditions at CBP detention facilities and its medical care practices is needed immediately."