LOS ANGELES, July 30 -- The Trump administration had forcefully separated more than 900 children from their parents at the U.S.-Mexico border over the past year in defiance of a previous court ruling, the American Civil Liberties Union (ACLU) alleged in a court filing on Tuesday.

In a 218-page lawsuit document, the ACLU told the U.S. District Court for the Southern District of California that "the government is systematically separating large numbers of families based on minor criminal history, highly dubious allegations of unfitness, and errors in identifying bona fide parent-child relationships" and this move must be stopped in accordance with the San Diego-based court's order issued last year.

According to the basic premise of the Court's preliminary injunction ruling in June 2018, "children should not be taken from their parents absent a determination that the parent is genuinely unfit or presents a true danger based on objective facts," however, the U.S. Immigration and Customs Enforcement (ICE) "separated children from adults on the basis of any criminal history, no matter how minor, old and unproven," said the ACLU.

The ACLU quoted ICE's most recent report of ongoing separations provided to the leading human rights group in the United States saying that from June 26 of last year, the date of the preliminary injunction issued, through June 29 this year a total of 911 child separations were listed.

The analysis found that 678 of these separations were based on allegations of criminal conduct, while the remaining separations were based on a range of reasons, including alleged gang affiliation (71 parents); allegations of unfitness or child safety concerns (20 parents); "unverified familial relationship" (46 parents) and parent illness (24 parents).

The filing showed three of the parents had been separated with their children because of traffic violations, 14 for DUI offenses, 15 for drug possession, and eight for fraud or forgery offenses. In many cases, the ACLU said, "it is unclear whether the parent was even convicted for the relevant offense, or merely charged."

The filing also alleged that separations were happening because ICE unjustifiably doubted the familial relationship between the parent and the child.

The government's own statistics showed that 185 children, more than 20 percent of the 911 children, were younger than five years old and 13 of these children were younger than one year old at the time they were separated from their parents.

Meanwhile, the filling showed some separations were occurred because of unsubstantiated allegations of abuse or neglect. In one example, a father was reportedly separated from his three young daughters because the father has HIV. In another example, a migrant father lost his daughter when a Border Patrol agent called him a bad father for allegedly failing to change his daughter's diaper.

Lee Gelernt, lead attorney in the family separation lawsuit and deputy director of the ACLU's Immigrants' Rights Project, called the revelations "shocking" in a statement issued to media on Tuesday.

"It is shocking that the Trump administration continues to take babies from their parents. Over 900 more families join the thousands of others previously torn apart by this cruel and illegal policy. The administration must not be allowed to circumvent the court order over infractions like minor traffic violations," he said.

Tuesday's filing was part of an ongoing lawsuit over the Trump administration's "zero tolerance" policy toward migrants who illegally cross the U.S. southern border.

The policy prompted a domestic and international outcry. Under political pressure, U.S. President Donald Trump signed an executive order in June 2018, saying that the U.S. government would stop separating families unless the adults pose a risk to their children.

However, according to the ACLU, few of the more than 900 children taken from their parents since June of last year were at risk, and the organization has condemned the deplorable conditions in which the children are detained.