SEATAC, Wash. (CBS/AP) — Massachusetts is joining Washington and more than a half-dozen other states that said Thursday that they plan to sue the Trump administration over a policy of separating immigrant families illegally entering the United States.

Washington Attorney General Bob Ferguson made the announcement Thursday outside a federal prison in the city of SeaTac, south of Seattle, where about 200 immigration detainees have been transferred — including dozens of women separated from their children under the administration’s “zero tolerance” policy. It calls for prosecuting all migrants caught illegally entering the country.

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Ferguson said the separations violate the due process rights of children and their parents and that President Donald Trump’s executive order Wednesday halting the practice has not resolved the legal concerns.

“This is a rogue, cruel, and unconstitutional policy,” Ferguson said. “We’re going to put a stop to it.”

The lawsuit would be filed in the U.S. District Court in Seattle.

The states set to join Ferguson’s lawsuit are Massachusetts, California, Maryland, Oregon, New Mexico, Pennsylvania, New Jersey and Minnesota. New York has separately announced plans to sue.

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“We are suing the President to put an end to his cruel policy of separating immigrant families,” Massachusetts Attorney General Maura Healey tweeted Thursday. “The President’s words cannot be trusted. Since the Administration won’t do the right thing, we will.”

A U.S. judge in San Diego is considering whether to issue a nationwide injunction sought by the American Civil Liberties Union that would order the administration to reunite 2,300 children with their parents.

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