Washington (CNN) The American Civil Liberties Union asked a federal judge to block the Trump administration from separating migrant children from their parents, claiming that more than 900 children, "including numerous babies and toddlers," have been separated since late June 2018.

Tuesday's filing is regarding separations that occurred after the administration's controversial "zero tolerance" immigration policy resulting in family separations had ended.

last year except in cases where a parent is unfit or presents a danger to the child. But the A federal court had ordered family separations to endlast year except in cases where a parent is unfit or presents a danger to the child. But the ACLU filing Tuesday maintains that US Customs and Border Protection agents continue to do so despite the court order, based on minor offenses like traffic violations.

"Some of the separations are for offenses that took place many years ago. And some are for mere allegations or arrests without convictions," the filing reads.

The filing includes anecdotes of children separated from parents upon entry into the US. In one case, three young sisters were allegedly separated from their father last November because of his HIV-positive status, according to a declaration by Kids in Need of Defense, an advocacy group for unaccompanied migrant children.

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