Immigrant advocates are accusing the U.S. government of "effectively disappearing hundreds of minor children" in a new complaint to an international human-rights agency.

The complaint announced Thursday targets the Trump administration's separating of parents and children crossing the U.S.-Mexico border.

Attorney General Jeff Sessions said in early May that authorities would start prosecuting every person suspected of having crossed the border illegally. That's resulted in hundreds of adults being jailed and their children often placed into federal shelters for unaccompanied immigrant minors.

Advocates say many parents have lost track of their children in the process. The complaint was filed with the Inter-American Commission on Human Rights, which studies alleged human rights abuses in North and South America.

U.S. Immigration and Customs Enforcement says it is committed to connecting parents and children "as quickly as possible after separation."