Marines deployed by US President Donald Trump temporarily detained a civilian on Friday at the Wilshire Federal Building in Los Angeles, the first known incident of its kind amid ongoing protests over ICE raids, the US military has confirmed.A spokesperson for the US Northern Command clarified that while military personnel are not authorised to make arrests, they may temporarily detain individuals “in specific circumstances.” Such detentions, the spokesperson said, end immediately once the individual can be safely handed over to civilian law enforcement. The detained individual, 27-year-old Marcos Leao, later told reporters he was an Army veteran and had been on his way to a department of veterans affairs office when he inadvertently crossed a yellow tape boundary and was stopped. Leao, who became a US citizen through military service, said he was treated fairly. “They’re just doing their job,” he said.Video shows Marines restraining the man with zip ties before handing him over to personnel from the department of homeland security (DHS). The active duty forces took over security duties at the federal building earlier on Friday, as part of a broader deployment in response to days of protests over immigration raids. Currently, 200 Marines and over 2,000 National Guard members are stationed in LA to protect federal property and personnel. An additional 500 Marines and 2,000 National Guard troops are expected to join them.Under the Posse Comitatus Act, the US military is generally prohibited from engaging in civilian law enforcement activities. However, Trump could expand military involvement by invoking the Insurrection Act, which would allow troops to directly enforce laws on the US soil.