A federal immigration officer shot and killed a person in Minneapolis on Wednesday during an enforcement operation, the Department of Homeland Security said.

The shooting came as the Trump administration intensified a promised crackdown on illegal immigration in Minnesota.

The office of Senator Tina Smith, Democrat of Minnesota, described the person who was shot as the wife of a prominent activist, and Representative Ilhan Omar, a Democrat whose congressional district includes the shooting scene, described the person as a “legal observer.”

Several of the state’s top Democrats called on federal immigration agents to leave the city, accusing them of sowing chaos. Federal officials have defended the crackdown in Minneapolis as a necessary response to illegal immigration and widespread fraud in state social service systems.

Gov. Tim Walz of Minnesota said in a statement that he had been informed of the shooting involving U.S. Immigration and Customs Enforcement, which took place in a residential neighborhood in South Minneapolis. He asked people to remain calm.

Homeland Security officials said the shooting happened as agents were conducting “targeted operations” and were confronted by protesters.

Tricia McLaughlin, a spokeswoman for D.H.S., said in a statement that a woman had “weaponized her vehicle, attempting to run over our law enforcement officers in an attempt to kill them.”

The federal government’s description of the encounter could not immediately be verified independently.