Having been deployed to Los Angeles by President Donald Trump in order to quell protests against ICE, U.S. Marines detained their first civilian on Friday: an Army veteran on his way to the Department of Veterans Affairs.

Maj. Gen. Scott Sherman, commander of Task Force 51 who is overseeing the 4,700 troops deployed, said Friday that the Marines have finished training on civil disturbance.

The unprecedented mobilization of Marines in Los Angeles and threats from a Florida law enforcement official to kill protesters took place on the eve of mass demonstrations across the country against the attempt by Donald Trump to establish a military dictatorship in the US.

Marines deployed to Los Angeles temporarily detained a civilian on Friday, the U.S. military confirmed after being presented with Reuters images.

The development comes a day after an appeals court temporarily blocked a judge’s order that directed President Trump to return control of the California National Guard.

Exclusive: Marines deployed to Los Angeles carried out the detention of a civilian, the US military confirmed after being presented with Reuters images, in the first known detention by active-duty troops deployed there by President Donald Trump https://t.co/g5eHP4rrEd

The deployment of troops to Los Angeles raises questions about what Trump can and can't do with the military on U.S. soil, and whether he's crossing the line.

San Francisco — A federal court hearing is scheduled for Thursday on whether the Trump administration can use the National Guard and Marines to assist with immigration raids in Los Angeles.