The U.S. Marines detained their first civilian protester in Los Angeles Friday, U.S. defense officials told Fox News. 

The civilian, who has not yet been identified, was temporarily detained and handed over to law enforcement, according to authorities.

Marines arrived in the city Friday after training for days for potential encounters with protesters.

Maj. Gen. Scott Sherman, leading Task Force 51, which is managing the National Guard and Marines’ deployment to Los Angeles, addressed the media Wednesday, June 11, 2025, at the Joint Forces Training Base in Los Alamitos, Calif. (AP Photo/Amy Taxin)

Organized by No Kings, protesters will gather for a “nationwide day of defiance” in thousands of cities across the U.S.

“Across city streets and small towns, from the steps of courthouses to local parks, we’re taking a stand against authoritarianism — and demonstrating to the world the true essence of democracy,” the organization shared on its website. “The flag isn’t President Trump’s to claim. It belongs to all of us. We’re not just observers of history. We’re actively shaping it.”

Los Angeles authorities said they have increased patrols and are prepared for potential escalations.