The Justice Department sues Maryland over a state law that bars federal law enforcement officers from wearing masks while working in Maryland and requires them to identify themselves. The lawsuit is filed on Thursday, the same day the law takes effect, according to reporting from multiple outlets.

The complaint targets Maryland and two large counties, Montgomery County and Prince George’s County. The DOJ argues that the jurisdictions are unlawfully trying to regulate federal officers and federal law enforcement activities through the new requirements. Several sources describe the dispute in the context of ICE, noting that the challenged provisions would restrict masking by U.S. Immigration and Customs Enforcement agents while they perform their duties.

Outlets characterize the action primarily as a legal challenge to Maryland’s and the counties’ authority to impose face-covering and identification rules on federal agents. Coverage also emphasizes that the lawsuit is filed immediately as the law begins to operate, setting up early court consideration of whether the state and local measures can be enforced against federal personnel.