Trump administration officials have revealed that an additional 1,712 migrant children may have been separated from their parents while coming into America.

The children entered the country before President Donald Trump enacted his “zero tolerance” policy a year ago, resulting in the separation of at least 2,800 children from their parents.

There is “preliminary indication of separation” involving these children, Commander Jonathan White of the U.S. Public Health Service Commissioned Corps said in federal court in San Diego Friday, CNN reported.

Even more children could eventually be identified. White said Friday his team has reviewed 13,000 files out of a total of some 47,000.

U.S. District Court Judge Dana Sabraw has given the administration six months from April to review all the files, even though Trump officials requested two years to track down all the children.

The new list of 1,712 children has now been sent to Customs and Border Protection for the “next phase of review,” to further track the children, White told the court, NBC reported.

The children at the center of the court case filed by the American Civil Liberties Union have already been released from government custody, the vast majority to parents or close relatives. But CBP records tracking them are spotty.

Following a federal judge’s earlier order, the government managed to reunite close to 2,700 children separated from their parents under the zero tolerance policy that prosecuted everyone entering the U.S. illegally from Mexico.