In stark demonstrations of U.S. President Donald Trump's assault on those without documentation, federal officials armed and wearing masks conducted extensive immigration raids in Los Angeles on Friday, while others pounced on migrants outside a courthouse in New York.

From courthouses to hardware store parking lots in two of the most diverse cities in the world, federal agents wrestled migrants into handcuffs and unmarked vehicles.

Agents used extreme tactics, conducting unprecedented raids on at least three areas of Los Angeles to detain dozens of people.

At one sweep less than two miles from Los Angeles City Hall, agents threw flash-bang grenades to disperse angry crowds of people following alongside a convoy of Immigration and Customs Enforcement (ICE) vehicles as protesters hurled eggs and epithets at the agents, media reported.

'Terror'