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, head of Task Force 51, which is overseeing the deployment of the National Guard and Marines to Los Angeles, speaks to reporters 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.

“From city blocks to small towns, from courthouse steps to community parks, we’re taking action to reject authoritarianism — and show the world what democracy really looks like,” the organization wrote on its website. “The flag doesn’t belong to President Trump. It belongs to us. We’re not watching history happen. We’re making it.”

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