Officials were scrambling Monday to establish rules to guide Marines who could be faced with the rare and difficult prospect of using force against citizens on American soil.

The operation, led by Major General Scott M Sherman, comes amid clashes over Immigration and Customs Enforcement (ICE) raids. “The activation of the Marines is intended to provide Task Force 51 with adequate numbers of forces to provide continuous coverage of the area in support of the lead federal agency,” the press release stated.

The U.S. military is set to temporarily deploy about 700 Marines to Los Angeles while additional National Guard troops arrive in the city, a U.S. official told Reuters on Monday. About 300 California National Guard troops were deployed to the streets of Los Angeles on Sunday to help quell a third day of protests over President Donald Trump's immigration enforcement,