The Department of Justice announced Thursday it has filed a lawsuit against Maryland and state Attorney General Anthony Brown over their sanctuary policies.

The Justice Department alleges the policies interfere with the federal government's enforcement of its immigration laws.

The DOJ took aim at the Community Trust Act, which limits how much state and local law enforcement can cooperate with federal immigration authorities.

The department said Maryland's refusal to cooperate with federal immigration authorities has already had negative operational consequences for federal immigration law enforcement, with facilities refusing to assist in transferring illegal aliens to federal custody even when presented with a routine detainer.

Sanctuary policies are illegal under federal law, the Justice Department said. Maryland's intentional efforts put U.S. citizens at risk and are preempted under the supremacy clause of the Constitution, the department said.

The Department of Justice has now filed 20 lawsuits against other states with sanctuary policies, including Colorado, Connecticut, Illinois, and New York.

A spokesperson for Maryland Gov. Wes Moore pushed back against the DOJ lawsuit.

"Maryland will work with the federal government when that coordination makes our people safer — but we will not let Donald Trump's untrained, unqualified, and unaccountable ICE [Immigration and Customs Enforcement] agents deputize our law enforcement officers to do immigration work," spokesperson Rhyan Lake said.

Moore did not sign the Community Trust Act into law. He let it go into effect without his signature.