The order, which takes effect at noon on Friday (Los Angeles time), said the deployment of the Guard was illegal and both violated the Tenth Amendment and exceeded Trump’s statutory authority.

The White House had no immediate comment on the ruling.

US District Judge Charles Breyer said Trump overstepped his bounds in ordering the deployment of roughly 4000 National Guard members to Los Angeles after protests erupted over the immigration crackdown.

It was not immediately clear how that would change the situation on the ground.

California Governor Gavin Newsom sued to block the Guard’s deployment against his wishes.

California later filed an emergency motion asking the judge to block the Guard from assisting with immigration raids.

He argued that the troops were originally deployed to protect federal buildings and wanted the court to block the troops from helping protect immigration agents during the raids, saying that involving the Guard would only escalate tensions and promote civil unrest.

In a broad ruling, the judge determined Trump had not properly called the Guard up in the first place.

Major General Scott Sherman, speaking in an interview with The Associated Press and one other media outlet, said that as of Wednesday about 500 of the Guard troops have been trained to accompany agents on immigration operations.

Photos of Guard soldiers providing security for the agents have already been circulated by immigration officials.

Sherman is commander of Task Force 51, which is overseeing the Guard troops and Marines sent to Los Angeles.

Earlier in the day, Breyer said he intended to rule quickly.

“This country was founded in response to a monarch, and the Constitution is a document of limitations. I’m trying to figure out where the lines are drawn,” the judge said before a packed courtroom.

Homeland Security Secretary Kristi Noem pledged to carry on with the Trump administration’s immigration crackdown despite waves of unrest across the US, while in Texas thousands of National Guard troops were on standby in case more trouble breaks out.

The developments unfolded as cities nationwide braced for major demonstrations against Trump over the weekend, and their leaders pleaded with residents to protest peacefully.

Noem said the immigration raids that fueled the protests will move forward, saying agents have thousands of targets.

“This is only going to continue until we have peace on the streets of Los Angeles,” she said during a news conference that was interrupted by shouting from US Senator Alex Padilla, a California Democrat who was forcibly removed from the event.

Newsom has warned that the military intervention is part of a broader effort by Trump to overturn norms at the heart of the nation’s democracy.

He also said that sending National Guard troops on the raids has further inflamed tensions in Los Angeles, where large and sometimes volatile protests have broken out since the crackdown began nearly a week ago.

So far, the protests have been centred mostly in downtown LA near City Hall and a federal detention centre where some immigrants are being held.

Much of the sprawling city has been spared from the protests.